Hi Nightraptor,
Subject to confirming that any retailer or manufacturer on the list you plan to visit is completely transparent (see this article) and to making sure that any mattress you are considering meets your specific criteria and the quality/value guidelines here … the better options or possibilities I’m aware of in and around the Minneapolis/St Paul area are listed in post #2 here.
You can see some comments about the quality and durability of the materials in the Helix mattress along with many of the other “simplified choice” mattresses in post #2 here in the simplified choice mattress topic but it uses lower quality/density materials than the minimums I would normally suggest in your weight range/ BMI (see the durability guidelines here)
You can also see some comments about the Luxisleep mattress in post #10 here. I would add a “slight” caution because of the 1.8 lb polyfoam base layer they use but with 6" of foam layers on top of the base layer it’s unlikely that it would compromise the durability or useful life of the mattress relative to your weight range/BMI.
I don’t keep a record of the individual mattresses or their specs that the retailers and manufacturers in the hundreds of forum lists throughout the forum carry on their floor or have available online (it would be a bigger job than anyone could keep up with in a constantly changing market) but checking their websites and making some preliminary phone calls to the retailers/manufacturers that are on the local lists is always a good idea before you decide on which retailers or manufacturers you wish to deal with anyway. This will tell you which of them carry mattresses that would meet your specific criteria, are transparent about the materials in their mattresses, and that carry the type of mattresses that you are interested in that are also in the budget range you are comfortable with. Once you have checked their websites and/or talked with the ones that interest you then you will be in a much better position to decide on the ones that you are most interested in considering or visiting based on the results of your preliminary research and conversations.
Having said that … many component latex mattresses have side to side split layering that allows you to customize each side of the mattress individually (in queen size or larger).
There is more about the pros and cons of a component latex mattress with a zip cover and loose layers vs a finished mattress with glued layers in post #15 here and Post #3 here includes a list of many of the online manufacturers that sell component latex mattresses as well.
For local choices if you don’t mind purchasing individual layers and a cover and putting together your own DIY mattress where all the layers and components haven’t passed the fire regulations “as a complete mattress” then diynaturalbedding carries latex layers and covers where you can make a side to side split latex mattress as well.
Moss Envy also carries Savvy Rest mattresses that offer side to side splits but these are in much higher budget ranges than other very similar mattresses.
Phoenix