I have 2 pair of shorts from Aerotech Designs: http://www.aerotechdesigns.com/bigsize.htm

I've got one of the Pro Bike Shorts, and one of the Classic Bike Shorts.

I actually prefer the classic to the pro (even though they're cheaper), since the pro has a rubber band around the bottom of the thighs which is a little tight at the moment, whereas the classic are simply spandex.

Bought the pro because I was experiencing extreme chafing with the classic and foolishly blamed the bike shorts; turned out it was the saddle and once I switched to a Brooks all is right with the world.