Hey if you're in Lorton you should also check out Northern Virginia Archers. Its a great range with aot of good people and a fair trad following. I'm a member as is Canopyboy (Dave Grant), Kingsnake (sp?), Killdeer, and a few others.
Regarding the wood, you can get some decent Ipe in 2x4x8' pieces from smoot lumber in alexandria.
I just bought a 2x4 of it and havent cut it yet, but if you're interested in a piece let me know, I've been meaning to go bother Canopyboy for some shop time anyway. Shoot me a PM if you're interested, you can have a slice of it at cost. I think it's like $15 for a slice 1.5" wide x ~1" thick x 8ft long ... plenty for a backed bow and a riser. Smoot won't cut it so I've got it whole still.