congrats on the purchase!
(btw, i think my 20's are just right!)
+1 on Poco's comments though. It's a critical purchase, one that will be with ya for a long time! The down side to the 20's is finding a good tire place to work with them. At least, here that is a problem. Most outfits here can't work with such large rims. I had a flat and it took me a long time to find someone i could trust to pull the rubber off, and remount them.