Hi Debbie,
Just in case you haven’t read it yet the first place I would start your research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choice … and know how and why to avoid the worst ones.
I would be very cautious about using mattress reviews (positive or negative) to help you assess whether a mattress may be suitable for you in terms of PPP (Posture and alignment, Pressure relief, or Personal preferences) or the durability of a mattress or as a reliable source of mattress research or information and in many cases they can be much more misleading than helpful (see post #13 here).
Having said that … I would also be very cautious before choosing an airbed and you can see my comments about them in this article.
There are certainly many great quality mattresses that would be in a much more reasonable budget range and I would question whether any mattress purchase in that budget range would be “worth it” for most people. There are also some suggestions in the first part of post #2 here that may be helpful for couples that have very different body types or sleeping positions and have very different needs or preferences but of course your own testing (with both of you on the mattress) will always be the most reliable way to know whether any specific mattress is a good match for both of you in terms of PPP.
The better options and possibilities I’m aware of in the Lubbock, TX area (subject to the guidelines here) are listed in post #2 here.
I don’t think any of these have customizable mattresses available although they may carry a non customizable mattress that has a design that is a good match for both of you. The mattress shopping tutorial also includes a link to a list of the members of the site that sell mattresses online (in the optional online step) and many of them make latex mattresses that use different types and blends of latex that have a range of different options and designs that are in much lower budget ranges and many of these are component designs that can be customized for each person and also have side to side split options available as well.
Phoenix