Hi solidary121,
Welcome to the Mattress Forum! … and congratulations on your marriage 
If you’ve been reading the site for a year then you’ve probably read it already but just in case you haven’t the first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and more importantly know how and why to avoid the worst ones.
The process of looking for a mattress would involve the same steps in the tutorial for someone who is heavier as someone who is lighter but you will likely need firmer materials than average, possibly a thicker mattress, and you would need to put a greater emphasis on more durable materials as well. Post #3 here also has more information that would be helpful for those with larger or heavier body types.
There is more about the many variables that can affect sleeping temperature in post #2 here that can help you choose the combination of materials and components and the types of mattresses that will have the best chance of keeping you in a temperature range that you are comfortable with.
Being a newlywed I should also mention that it can be important that a mattress is a good “match” for some of the other activities that happen on a mattress and if you are considering memory foam then it may also be worth considering or at least testing other types of materials and mattresses that are more resilient and have more “bounce” so that you are are confident that you are OK with the properties and slow response of memory foam (see post #2 here).
As you can see in the guidelines here I would avoid any of the major brands such as Serta because the quality and durability of the materials they use (in the comfort layers especially) are questionable at best and a mattress that uses higher quality and more durable materials and doesn’t have any “weak links” would be especially important in your weight range. No matter how comfortable a mattress may be or how well you may sleep on it there would be little value in buying a mattress where the materials inside it soften or break down prematurely and you lose the comfort and support that was the reason you purchased it and need to buy a new mattress much too quickly relative to the price you paid.
You can see my comments about the Consumer Reports mattress ratings and recommendations in post #2 here and in this topic. While they may be a good source of information about more “objective” purchases … as you can see I would consider them to be an unreliable source of information or guidance about purchasing a mattress. My thoughts are shared by most of the more knowledgeable people in the industry (see post #5 here for an example). Having said that … at least the Charles P Rogers mattress you are considering would be a good quality choice.
I would also be very cautious about using other people’s experiences or reviews on a mattress (either positive or negative) as a reliable source of information or guidance about how suitable or how durable a mattress may be for you and in many cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person may be completely unsuitable for someone else to sleep on either in terms of suitability or durability (see post #13 here).
You can see some comments about the Casper mattress along with some of the other “one choice fits all” mattresses in post #3 here and there is also more information about them that would be relevant for higher weight ranges in post #3 here.
I don’t have any specific suggestions because you are the only ones that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved for anyone to be able to predict or make a specific suggestion or recommendation about which mattress would be the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own personal testing or sleeping experience (see mattress firmness/comfort levels in post #2 here).
Having said that … the “best” general suggestion I can make about “how” to choose would be to follow all the steps in the tutorial one at a time which would give you the best chance of making the most suitable, the most durable, and the best “value” choice based on all the criteria that are most important to you (including your budget range of course).
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress that is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability, durability, and value.
The tutorial includes two links to lists of some of the better online options that I’m aware of (in the optional online step) that would include many options in your budget range and some of the better lower budget latex and latex hybrid mattresses I’m aware of are also listed in posts #3 and #4 here.
If you let me know your city or zip code I’d also be happy to let you know about any of the better options or possibilities I’m aware of in your area as well.
Phoenix