After 5+ years we finally found a solution.  I wanted to wait a few weeks to be sure, now I am.  This bed is incredibly comfortable and provides perfect hip support for us (we're side-sleepers, I'm 5'10" 150# and my partner is 6'0" 170#).

The combo is a McRoskey Queen mattress (Gentle model, $1950), over a low-profile, Chattam & Wells 8-way hand tied box spring (retail on this was $1600, Mancini's have a few in back stock and we were able to talk them down to $550).

For a matching set, I assume McRoskey's 8-way hand tied box spring would be as comfortable, but it costs the same as the mattress ($1950).

Unlike the S companies, who play games with specs and model names, these exact same components can be duplicated by others who wish to try this specific combo.  If you're currently on the foam (or air) treadmill, but can't find a decent night's rest to save your life, I highly recommend it.  There's not a bit of foam to be found in the mattress, it uses traditional cotton and poly batting for its comfort layers and should easily last 20+ years.

Jim