What tubes and where to buy them? Conrad Johnson

Hello!

I`m from Brazil but currently I`m doing part of my PhD at University of Florida.

Back in Brazil I have a Conrad Johnson Premier 3 pre amplifier and a MV55 power amplifier.

I need to buy a new set of tubes for both, since it`s very hard to find tubes in Brazil.

The tubes they use are:

Premier 3: 2 12AX7, 5 5751, 2 5965
MV55: 2 12AX7, 2 6SN7, 4 EL34

I would really aprecciate some advice on what tubes I should buy and specially where can I buy trustable audiophile tubes, and not guitar amp tubes. I`m looking for a cost effective option because I won`t be able to spend a huge amount of money with that.

Also, I would like to know what tubes should I start changing if I can`t afford changing it all.

Thank you vety much!