My favorite vendor is Bob Bieker :
http://radioantiques.com/ He only shows up at the Illinois meets, but if you can't wait for the next one you can order from him online or by phone.
I like his starter kits :
http://radioantiques.com/supplies.html#capkits They give enough values to replace most tubulars in radio and TV applications for a decent price.
Some of Bob's lytics are a bit on the expensive side, so I've been thinking of finding better vendors online.
I don't trust Chester's lytics much.....I have a Heathkit C3 cap tester that can check for leakage at up to 450V, and my only lytic purchase from Chester's which was full of old stock caps had quite a number of caps that tested far enough from new to make me think twice about installing them.....