I am happy with the REI brand Novara shorts - both their double rail shorts or their traditional road bike shorts. They also have a no hassle return policy - even if you wear them and decide you don't like them, they will take them back. They only ask that you launder them first. Their closest store is Chicago area, but of course you can order online. I wore the road bike shorts on a 10+ hour 100 mile mountain bike ride and they were great. They are reasonably priced too.

http://www.rei.com/search?cat=450012...Brand%2CNovara