Made a day trip to all the wrecking yards around Sacramento and the SF Bay Area yesterday. Diddn't find much.
Lots of things that bolt directly to the rear door, tailgate or door hinges of vehicles. Unfortunately not made for the weight of a 35" spare.
Lots of things that mount to the truck body above and below the rear tail light like the first gen blazers. But like Mike said, these fit to the rear contour of the vehicle and the back of the suburban is unique.
I love what BobbyK did for his blazer. Thanks for posting the step by step in the FOTKI gallery. That's the kind of info you can't get anywhere else and a clear illustration of why this forum is such an invaluable asset to it's members. I'll be sure to leave plenty of clearance for the rear tail light if I try fabricating one for myself though