I have my dad's '68 Ampeg Gemini.

It takes:

3----- 12AX7's

2----- 7591's

1----- 7199 (tremolo/reverb?)

1----- 6CG7 (rectifier?)

The 12ax7's I can get no prob.

Do they still make 7591's? what about the 7199 and the 6CG7?

If so where can I get them? for how much?

Also what are best brands for each tube?