Hey, y’all!
After weeks of deliberation, I’ve decided my best option is DIY, but I still need some advice as I’m drowning in possibilities. I’ve read through the introductory guide and I’ve got some ideas, but I’d really like to hear what y’all would propose for my build based on the following:
Sleeper profile: 5,9", 160lb, 80% back 20% side sleeper
Ideal mattress: Full size, will likely last >5 years, medium support, with a bit of bounce, and a soft, yet not too soft that I feel stuck, foam top. I would think a combo of latex/memory foam for a comfort layer would be ideal, but I’ve never felt that combo together, only separately.
Budget: <$600 but can go to $700 if worth it
Any input is appreciated
Hi Yomakkas.
Welcome to our Mattress Forum. 
Regarding beginning a new DIY project, the first place I would start is by reading option 3 in post #15 here and the posts it links to (and option #1 and #2 as well) so that you have more realistic expectations and that you are comfortable with the learning curve, uncertainty, trial and error, or in some cases the higher costs that may be involved in the DIY process. While it can certainly be a rewarding project … the best approach to a DIY mattress is a “spirit of adventure” where what you learn and the satisfaction that comes from the process itself is more important than any cost savings you may realize.
If you decide to take on the challenge then I would either use the specs (if they are available) of a mattress that you have tested and confirmed is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) as a reference point and try and “match” every layer and component in your reference mattress (including the type and blend of latex, the thickness of each layer, and the firmness of each layer as well as the type of cover as well) as closely as possible or use a “bottom up” approach (see post #2 here).
Additionally, It is impossible for anyone to tell with certainty which configuration is the best match for each sleeper as this is completely dependent on each of the sleeper’s BMI, body type, profile, and of their needs and preferences. Typically, a side sleeper in a normal BMI range can do well with anything between 2 - 4" comfort layer. There is more about the factors that can affect the durability and useful life of a mattress relative to different people (with different weight ranges and sleeping styles) in post #2 here and the posts it links to.
Now, onto your ideal mattress! You mention a bit of bounce, which to me sounds like you’d be happiest with a hybrid of sorts as opposed to an all foam configuration. And, as primarily a back sleeper, you can also get away with less thickness in your comfort layer.
A hypothetical suggestion as a starting point here would be a 6" - 8" coil system with 2" of transition foam (latex) and 2" of comfort layer foam (memory foam).
Can I inquire as to why you want mixed latex/memory foam and not all of one or the other?
NikkiTMU