a319 are very strong rims, stronger and cheaper than a719, I even use 'em on my 29er MTB. Lowest cost source for wheels is bicyclewheelwarehouse.com. I can't buy the parts as cheap as the built wheels from bww. Here's a good set of a319/Deore/DT for the street:

http://www.bicyclewheelwarehouse.com...d&productId=79