Hi solstice016,
I would again avoid the temptation of getting too caught up in terminology. In essence, you’re considering using 1" or 2" of memory foam beneath the upper latex layer. The extra 1" of memory foam will allow for a bit more of a dense feel deep down, but will also allow for a bit more deflection and “sinking in”. There is also more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel” that may be useful as well.
Deep support Is primarily from the support core within the mattress, but extra padding on top can allow for sinking in more deeply, which for some prone sleepers can be problematic. But I would have no way of telling how either of you would react to either configuration you’re considering – I can only explain the differences.
Phoenix