Hi sleepycarl,
Just in case you haven’t read it yet … the first place I would begin your research is the tutorial post here which has all the basic information, steps, and guidelines that can help you make the best possible choices … and learn how to avoid the worst ones.
Until I learn how to clone myself so I can “take turns” sleeping … I’m just one person that spends a LOT of time on the forum and with the other research and activities that are part of maintaining and growing the site 
As you’ve read … I would be cautious with any of the major brands unless you can confirm the quality of all the layers and that they are a good match for your personal value equation compared to other mattresses that are available to you. No matter what the “showroom feel” of a mattress may be … if the materials in the mattress are lower quality/density then the way it felt in the showroom can change much too quickly as lower quality materials soften and degrade and the mattress loses its comfort and support (which isn’t covered by warranty).
You can see my thoughts about the Edsele and some of the other Ikea mattresses in post #3 here. It’s made of 85% natural Dunlop latex which is a good quality material but of course it would also need to be a good match for you in terms of PPP to be a suitable choice.
Memory foam won’t have the durability of latex so that wouldn’t be an option. They are also very different materials and feel and respond completely differently. You can read a little more about how they compare in post #2 here. There is also more about “matching” one mattress to another in post #6 here but it’s not likely that you will find a mattress that is an exact match for another one unless they use exactly the same materials and components and materials in the same layer thicknesses and the same type of cover and quilting.
In most cases … there are just too many variables in mattress materials and design for it to be likely that one mattress would “match” another one in all ways that are important unless that was the goal of the mattress designer. In most cases it’s more effective to “measure” all mattresses you test against a common set of criteria and your personal value equation (see post #46 here) than it is to use one mattress as a “target” that you are trying to match which may limit you to trying to choose a mattress based on subjective perceptions alone that can quickly change (subjective memory is never particularly accurate) . Mattresses that used the same type of materials and components in the same layer thicknesses, firmness, and in the same density (if you could even find all of these out for your “target” mattress) would have a better chance of “matching” another mattress but there could still be significant differences depending on the specifics of the materials.
Some of the better options I’m aware of in and around Chicago are listed in post #2 and #4 here and it includes two sister companies (Quality Sleep and My Green Mattress) that are members of this site and would be among the first place I would visit … and possibly the last. They make and sell a wide range of mattresses.
The tutorial post also includes a link to the retailers and manufacturers that are members of the site that are among the better online choices I’m aware of.
They both are members here which means that I believe they compete well with the best in the industry in terms of quality, value, and service.
Phoenix