Go ahead and call OMF, they’re more than willing to give you the information - I ended up doing that myself for a couple of theirs.
Also, go back into the store, and try out the Latex mattress that they have in-store.
Check out: THIS THREAD and THIS THREAD BTW. They give some background of me looking at OMF, and then going with APM.
Something I’d highly recommend is checking out Sleep EZ. Not necessarily to buy (APM is much cheaper), but for their configuration tool. You can put in size/weight and sleeping style, and it will give recommendations. Once you have tried some stuff in-store and have a configuration in mind, give Ken (from APM) a call and talk to him about it. He was really helpful for us!
After doing a bunch of research, I decided to go with Arizona Premium…as I indicate IN HERE.
As for your concern about bed height. I’m assuming it’s not a matter of “wanting a thick mattress”, and it’s more of a “we want to be up higher off the ground”, right?
If so, one option is always to get a new bed-frame…but I assume you don’t wanna do that.
The other option is to get a platform/base/foundation - LIKE THIS. Now you can use a thinner mattress, but still be raised up higher.
Hope this helps!