I can't necessarily help you with parts directly, but I do know that 2strokeworld.com is the best forum for used RD parts. DG's can also be found for like $225 new on eBay. EconomyCycle.com is the best for new parts. Also, RD's Only is selling of a load of carbs and other bits.
http://www.2strokeworld.com/forum/index.php?topic=28581.msg210943;boardseen#new
You'll have to be a forum member to view it.