So we picked up our custom mattress made from this place:
http://themattressmaker.com/
They used our stock Airstream mattress for a template. We had it made 12" thick (you can have it made any thickness) with a pillow top the maximum that would fit in our space. I am going to relocate 2 electrical outlets that are now covered. That was planned.
The mattress is the Ultimate Luxury Collection "Rapture" and originally we were getting $600+/- quotes, but my wife upgraded last minute to this higher end line and it costs $900. A lot of money, but understand this is a luxury model and it is custom made with the radius corners and thickness.
It is heavier that the OEM mattress, but not a deal breaker. If you are tight on tongue weight it may be an issue.
I am very happy with our decision. It is truly a top end solution and I think we did the right thing.
I wish I could post pictures, I have some showing the thickness compared to OEM and installation.
Anyone in MA want the OEM mattress for free?