We've used a memory foam topper and that worked pretty well. But then we decided to have a custom mattress made to fit on one of our past RVs. That was much better because we could have it made the way we wanted AND try out a similar construction in the showroom.
Before mattress sales became a racket every major town had a mattress factory and many still do. That's who we used - Cantwell Mattress in San Antonio.
There are a couple of online custom mattress makers that specialize in RV mattresses.
www.mattressinsider.com is the one I see the most often mentioned.
Our current Class A came with a no-name brand "air mattress", trying to be Sleep Number wannabe. We didn't like it and replaced it with an online mattress seller, not custom made or anything. It was shipped in a box. It's worked very well.
The Froli system looks great, I just don't know anyone that's tried it.