I've checked around here and haven't found anything yet. It would be nice to find a local place so I can see and feel the foam before I buy it, but it is starting to look like I'll have to get it over the net.
What about a fabric shop?
You might could buy a memory foam wheelchair cushion...from Invacare, Mason or Span america, they are 3 manufacturers of foam cushions...
I had mine done just before Biketoberfest last year. It was better than it was before but I'm still not satisfied. In the process at looking at buying another seat.
I'd rather take my chances with an aftermarket seat that has a great track record such as a Mustang etc. But as said before not one seat fits all butts.....like windshields it is a crapshoot