Overweight sleepers looking at Memory Foam mattress options

My wife and I are overweight and wore out a Serta iComfort in about 4 years. The dips have started hurting our backs and we’ve started looking at something new. We started out with a Saatva king and although it had amazing reviews, we weren’t happy with it from the first night. It was loud and uncomfortable but we had been spoiled with 3 good years with the iComfort.

My wife has a bad back and I’m assuming we are going to get 3 years out of something new. Because of that, I don’t want to buy the overly expensive iComfort. I’ve checked out Amazon for reviews and the iComfort seems to be getting killed but the $600 Sleep Innovations, Dynasty Mattress, Brentwood and Signature Sleep all are getting great reviews.

Alternatively, I want to try out the Casper because of all the good reviews but I’m concerned the 10" foam will not be sufficient for two larger people.

I did do a forum search and didn’t see much so I apologize if I missed something. Any feedback is appreciated.