Hey David, check out this guy. I buy my radio tubes from him and his prices are the best I've found. He also will match tubes for you before he ships.
FindATube.com: Vacuum tubes by mail order, vintage radio parts, antique electronics
*Disclaimer* I am into old radios, so the audio stage is the end of my signal chain. I am NOT an amp guy!
I think that having a good quality American or European brand is best. I don't use Russian tubes (except nixies) and would stick to Sylvania, RCA, National Union, and so on. I also buy from a couple of other websites if Bob @ findatube doesn't have what I need.
Antique Electronic Supply
Vacuum Tubes Radio Tubes - 5,000 different tubes in stock - Over 10 million tubes!