Michael,
When I was thinking about building a scope I turned to Edmund Scientific...
http://scientificsonline.com/Default...cd2=1222947924
I don't know if they still cater to that market but I know they had tons of info and everything from mirrors to blanks, tubes and eyepieces. The best yet, they had an outlet here in Chicago that I could get to by bike. That was long ago and far away. Good Luck.