A build forum is a great idea. I agree that many members builds that have posted get lost in the general forum.
A build forum would be very helpful in that it would be a valuable source of information. Builds show the successes and possibly some failures of what a person can or can not do. Might even save a few dollars by not repeating someone else's mistakes.
Remember people. Success comes on the heals of failure and a build forum would have many succusses.