Pat: I've been using MA-2's and like them a lot. Someday I'd like to use stone-tipped cane with my osage selfbow. Just haven't had the time to get those together.
Sonny: I buy the shafts at Menard's. I think the franchise is localized in the Midwest, but I've seen them from time to time at the major home improvement retailers (i.e. The Home Depot, Lowes, etc.). Each time I go, I sort through all the 5/16" dowels in the rack for ones that are clear and straight grained. I bundle them up and store them until I get about 20 or 30. Then I cut them to 30 inches, sand them, straighten them, spine and weigh them, and then group them in bundles by spine weight. Heck, for $0.28 a piece, you can't hardly go wrong!