Just as important as the mattress is the stand/box spring. Those old metal coil frames are cheap and outdated and now top bed Combos have a low frame and sturdy center of gravity as the mattress will start to sag in places, even causing some back issues if it's not supported so you want a very sturdy base and/or boxspring.
Here's a pic of the beds in the suites at Mandalay Bay, solid and comfortable. They are selling their exact bed combo they have in their suites so I'm assuming it's pretty good. Gel infused foam. But they are asking $1500-$2500
Good luck
https://www.shopmandalaybay.com/product.aspx?mattress-and-box-spring
