Hi Silverion77,
Welcome to the Mattress Forum! 
As you probably know from reading the tutorial … it’s not possible to make specific suggestions or recommendations for someone else either for a mattress, a manufacturer/retailer, or a combination of materials or type of mattress because the first “rule” of mattress shopping is to always remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort” or PPP (Posture and alignment, Pressure relief, and Personal preferences) or how a mattress will “feel” to you based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or if you can’t test a mattress in person then your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
While your “request for input” is too broad to provide any specific suggestions or answers about what to choose … I can certainly provide some information that may be helpful with “how” to choose.
The choice between memory foam and latex is a preference choice rather than a “better/worse” choice (assuming that the memory foam isn’t less than 4 lb density which could be a weak link in the mattress). I would make sure that you are using the testing guidelines in the tutorial and when you are testing memory foam I would suggest spending a little extra time on the mattress so that the memory foam has a better chance to soften and warm up with your body temperature so you have a more reliable sense of how the mattress will feel over the course of the night. There is also more about the pros and cons and differences between memory foam and latex in post #2 here but the most reliable way to know which one you tend to prefer (at least in general terms) would be based on your local testing and your own personal experience on several mattresses that includes each material in the upper comfort layers.
The support core of a mattress isn’t generally the weakest link of the mattress in terms of durability so the choice between an innerspring (or pocket coil) vs a polyfoam support core (assuming that the polyfoam is a good quality/density material that meets the quality/durability guidelines here) would also be a preference and/or a budget choice rather than a “better/worse” choice.
Polyfoam is less resilient and responsive and somewhat “stiffer” and less “springy” or “bouncy” than an innerspring but it can also make a very good support system for those that are also a little more restricted in terms of their budget or for those that prefer how it feels over other types of support materials or components. Most of the “feel” of a mattress when you first lie on it comes from the upper layers but the deeper support layers will also contribute to how a mattress feels as well especially when you move or “bounce” on the mattress and the mattress is compressed more deeply. They can also have a more significant effect on how well you sleep over the course of the night and how you feel when you wake up in the morning. There is more about the different types of innersprings (which includes pocket coils) in this article and in post #10 here.
There are hundreds of different types of innersprings with different firmness levels and response curves that are used in conjunction with hundreds of different combinations of materials on top of them so there isn’t a single “feel” for innerspring mattresses that you can use to compare them to other mattresses because these types of comparisons depend on the specifics of the design and how a mattress feels to you “as a whole”. The same is true for mattresses that use polyfoam or latex support cores so the only way to know how two mattresses compare and the differences you would feel between them in terms of PPP (which may not be the same as someone else would feel if they compare the same mattresses) would be based on your own careful testing and/or personal experience.
There is more information about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel” although this may be more than you really need to know.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists (based on all the parts of your personal value equation that are most important to you).
I would always make sure that you are confident that a mattress is a good match for you in terms of “comfort” and PPP (or that you have a good exchange/return policy to fall back on if you aren’t), that you know the type and quality of all the materials and layers in the mattress (see this article) so that you can make sure that none of your finalists have any lower quality materials or weak links in the mattress (and I would avoid any mattress where you aren’t able to find out the quality and durability of the materials and components inside it), and that you make good comparisons between your finalists based on their suitability, durability, and all the other preferences and criteria that are important to you.
There is more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of comfort and PPP in post #2 here that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for once you actually sleep on your mattress but as you mentioned … when you can’t test a mattress in person (or if you can and you are still uncertain) then the most reliable source of guidance is always a more detailed conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart who can help “talk you through” the specifics of their mattresses and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept well on and liked that they are familiar with, any special considerations you may have, and the “averages” of other customers that are similar to you. They will know more about helping you to “match” their specific mattress designs or firmness options to different body types, sleeping positions, and preferences or even to other mattresses that they are familiar with than anyone else so that in combination with your own personal testing you can make the “best possible” choice with the highest chance of success.
If you let me know your city or zip code I’d be happy to let you know about any of the better options or possibilities I’m aware of in your area.
The tutorial post also includes several links to lists of the better online options I’m aware of as well (in the optional online step).
One of them is a link to a list of the members here that sell mattresses online that all compete well with the best in the industry in terms of their quality, value, service, and transparency. As a group they make a very wide range of of different types of mattresses and many of them also make latex and latex hybrid mattresses that use different types and blends of latex that have a range of different designs, options, features, return and exchange policies, and prices that that would be well worth considering.
One of them is a link to a list of the better online memory foam options for those that prefer memory foam.
One of them is a link to a list of the better lower budget online options I’m aware of.
And finally one of them is a link to a list of the new “breed” of “simplified choice” mattresses and most of these are also in a budget range that is less than $1000.
There is also more about the pros and cons of a local purchase vs an online purchase in this topic and the other posts it links to (in post #4 of the topic).
Once you are down to a list of finalists and you are confident that they would all be a good match for you in terms of PPP (or you have good options after a purchase if you aren’t) and that there are no lower quality materials or weak links in any of them in terms of durability then you would be down to finalists that are comparing “good to good”. If there are no clear winners between them at this point (which is usually a good indication that you have done some very good research) then you are in the fortunate position that any of them would likely make a good quality/value choice and (post #2 here) can help you make a final choice based on your local testing or mattresses you have slept well on, your more detailed conversations with each of them, your confidence about PPP and the suitability of each one, their prices, your preferences, the options you have after a purchase to fine tune the mattress or exchange or return the mattress or individual layers, any additional extras that are part of each purchase, and on “informed best judgement” based on all the other objective, subjective, and intangible parts of your personal value equation that are most important to you. Sometimes a final choice may even come down to very minor differences or can sometimes just be a matter of “gut feel” or “educated best judgement”.
Phoenix