diytube.com

This site, though located in China, has tons of parts, and they are dedicated to tube audio. Shuguang and Fullmusic tubes, teflon sockets, their own (branded) electro-caps, amp kits, bakelite and phenolic octal sockets for cheap, stereo pots, etc. Their shipping policy looks flexible - a number of carriers.

http://www.kdindustrial.com

They have a listing on alibaba for wholesale quantities. Might save some dough if you build a lot of amps.
http://kdindustrial.en.alibaba.com

I don't think I have ever received spam from them either. That puts them in my good books already