My "sleep number knockoff" I got from Costco failed after three years. I couldn't get a replacement air mattress and Costco is refunding it 100%. I liked it, but can't find another one for even twice the price.
I'm picking up a tempurpedic knock off from amazon.com with good reviews. It is a tossup for me between these two:
http://www.amazon.com/gp/product/B0050JL4LA/ref=ox_sc_act_title_9?ie=UTF8&m=AOFIBMXVIVCJ6
http://www.amazon.com/Sleep-Innovations-12-inch-Memory-Mattress/dp/B003CT37LA/ref=sr_1_1?s=home-garden&ie=UTF8&qid=1326870089&sr=1-1
As far as the bed frame goes, I'm changing from Calif King to Eastern King. To make a frame, I'm taking the basic "sliding" frame that adjusts and am putting in plywood panels. I got that idea from the 'net and the mattress ratings. If you don't have the means to cut plywood to fit, you can have them do it for you at Home Depot.