You said you already have a box springs, so try it out before you buy a new bed that you may not like. The box springs is firmer than the mattress above it, but it is not hard like the slat bed. A box springs "gives" slightly to your weight and movement. A solid platform bed has no give, so put your new mattress on the floor one night to experience how a solid foundation feels.

I have a 3 inch memory foam mattress topper than made a huge difference in how my bed feels. As I've gotten older I've found I need a softer, but still firm mattress. The topper made my bed feel so much better. While looking for this item I read many customer reviews. One couple had bought a new bed, then found it to be more firm and less comfortable than they expected. (How can you really tell how a mattress feels from laying on it for 5 minutes in a store?) They bought the same memory foam topper which fixed the problem. My and others' opinions are no substitute for your personal experience. Try out your new mattress as I've suggested above.

Latex mattresses are usually not used on a flexible base. They are supposed to be rigid. So, whether you are using a foundation, slat bed, platform bed, it should not affect the mattress feel what so ever. As far as the "boxspring" that needs to be defined. Here is a little more info http://www.stlb… What is a Box spring and What Does it Really Do?