Hi ls1dreams,
Welcome to the Mattress Forum! 
I’m assuming that you’ve read the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps most importantly know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you read are post #2 here which has 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 (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 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 (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).
[quote]In short, here’s what I’m looking for, so tips would be appreciated.
- I’m located in the Washington, DC metro area
- Normal/lightweight (160lbs)
- Looking for queen size
- Looking for < $1000
- I tend to be a side/stomach sleeper
- Prefer cooler beds
I read that you should ideally try to find a mattress with the top foam < 1" or so. Is that only for polyfoam, or does it apply to others as well?[/quote]
I would always keep in mind that the first “rule” of mattress shopping is to 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 your Personal preferences) or how a mattress will “feel” to you or compare to another mattress 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 your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
I or some of the more knowledgeable members of the site can certainly help you to narrow down your options, help you focus on better quality/value choices that are available to you either locally or online, help you identify any lower quality materials or weak links in a mattress you may be considering, act as a fact check, answer many of the specific questions you may have along the way that don’t involve what you will “feel” on a mattress, and help with “how” to choose but only you can decide which specific mattress, manufacturer, or combination of materials is “best for you” regardless of the name of the manufacturer on the label or whether anyone else has the same criteria or circumstances or would make the same choice.
The better options or possibilities I’m aware of in and around the Washington DC area (subject to making sure that any mattress you are considering meets the quality/value guidelines I linked earlier in this reply) are listed in post #2 here.
If you are also looking at online options then the tutorial also includes several links to lists of the better online options I’m aware of as well (in the optional online step).
Unless you have a great deal of knowledge and experience with different types of mattress materials and specs and different layering combinations and how they combine together and can translate them into your own “real life” experience that can be unique to you (which would only be a very small percentage of people) … I would tend to avoid using individual specs such as layer thicknesses or ILD numbers or other complex combinations of specifications to try and predict how a mattress will feel or perform for you and focus more on your own actual testing and/or personal experience. When you try and choose a mattress based on complex combinations of specs that you don’t fully understand then the most common outcome is information overload and “paralysis by analysis”. As you can see in the previous link choosing a mattress based on specs would be among the least reliable ways to choose a suitable mattress.
While your own careful testing or personal experience is the most reliable way to know whether a mattress is a good “match” for you in terms of comfort and PPP … when you can’t test a mattress in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart and who can help “talk you through” the specifics of their mattresses and the properties and “feel” of the materials they are using (fast or slow response, resilience, firmness etc) 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 on and liked or other mattresses you are considering that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs to different body types, sleeping positions, and preferences (or to other mattresses that they are familiar with) than anyone else.
Unfortunately it’s not possible to quantify the sleeping temperature of a mattress for any particular person with any real accuracy because there are so many variables involved including the type of mattress protector and the sheets and bedding that you use (which in many cases can have just as significant an effect on temperature as the type of foam in a mattress) and on where you are in the “oven to iceberg” range and because there is no standardized testing for temperature regulation with different combinations of materials … there is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range.
There are certainly durable mattresses available in your budget range yes.
It’s also not possible to quantify how long any mattress will last for a specific person or predict exactly when you will decide to replace it because it is no longer suitable or comfortable for you (because this is the only real measure of durability or the useful life of a mattress that really matters) because there are too many unknowns and variables involved that are unique to each person but if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new (see post #2 here) and meets the minimum quality/durability specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or even longer.
There is also much more detailed information about all the many variables that can affect the durability and useful life of a mattress relative to different people in post #4 here and the posts it links to.
I would be very cautious about brand shopping because you are buying a specific mattress not the brand and all manufacturers have access to the same or similar components and materials. Most of the more heavily advertised and most commonly available brands that you would recognize are the ones I would avoid anyway and many of the better manufacturers are smaller and are only available locally or regionally (or online). The name of the manufacturer on the label also won’t tell you anything about whether a specific mattress would be a suitable choice for you in terms of PPP or whether there are any lower quality materials or weak links in the design that would affect the durability and useful life of the mattress. There is more about the risks of brand shopping in post #5 here and post #12 here. Outside of careful testing for PPP (hopefully using the testing guidelines in the tutorial) or a more detailed conversation with a manufacturer or retailer about whether a mattress would be suitable for you if you can’t test a mattress in person … I would focus much more on the type and quality/durability of the materials inside a mattress (which are important to know anyway) than I would on the name of the manufacturer on the label.
There is more information about what I call “simplified choice mattresses” in general in post #1 here and there are some comments about Leesa and many of the other simplified choice mattresses in post #2 here in the same topic (this is one of the online links in the tutorial).
Phoenix