hello!
Bruce, I have been building these wonderful Multi's using standard road rim's available anywhere in the world.
It is my assertion that these multi rotors are the lightest, strongest, most available and least expensive multi frames out there.
Even better, they are reverse compatible with most larger sized multi's, like the s800 or similar.
I invite you to try the idea out!
http://www.rcgroups.com/forums/showthread.php?t=2109318