Tube Selection Help

I actually enjoy rolling tubes according to the music I'm listening to. Similar to using different strings on a guitar to change the sound. So many choices available.
I found Telefunken smooth plate 12ax7's to be loud and clear while Mullard's were mellow and deeper. Sovtek 12ax7lps's were horrible, Sylvania Gold Brand 5751 is my favorite input tube for my preamp (Sound Valves VTP101). RCA made great tubes back in the 50s-60s-70s and I have them too. Personally, I tend to favor military type triple mica /extra support rods input tubes because of their lower microphonic's. My point is that you should pick up an assortment and see what you prefer. Input tubes aren't too expensive and you don't have to worry about biasing.
NOS vintage El34's cost an arm and a leg. Mullard's are probably around $75 to $100 each but IMO have a more interesting sound than the current re-issues. YMMV.
Plenty of info out there. Read up about the different tube variants. For example 12ax7-12ax7a-5751-7025-ECC83-EC803S. Similar variations exist for 12au7's. Mix and match till you get the sound you want.

For the 12AT7s and 12AU7s I would go with Military Mullard tubes. They are readily available and the price is still reasonable. VTL really comes to life with those tubes. They use a different numbering system beginning with "CV".

Also, look for some NOS EI EL84s.

Whenever I am seeking a specific sound quality in tubes I always contact Jim McShane and Brent Jesse for advice and purchase. They always are spot on in their selection, no BS, and often are able to provide far cheaper alternatives which sound just as good or better than the most sought after wonder tubes. Just food for thought.

Thanks for all the responses. I think my plan is to stick with my current amps, but reach out to a recommend tube dealer for help to tailor the sound (hopefully some of the cheaper alternatives will work for me). I am also going to do some research on the current crop of around $500 and below DACs. Happy New Year!

If you can find an EL34 amp to sub into your system for a short time, do it. I think you will find that the EL34 is inherently warmer sounding with outstanding, and to my ears pleasing, midrange bloom. I have 3 EL84 amps presently but only one is employed. Admittedly none are VTL quality and none I own will put out your watts. I like the sound of EL84s and like them best in casual listening or background music. But to my ears even though EL84s sound nice they are bit thin and not as fleshed out as EL34s. Since your amps put out comparable power to a normal 4 tube EL34 amp it would be a good comparison! I wish I could bring mine over to compare.

My main amp, a TAD60, can take EL34s or KT88s. I have tried KT88s but prefer the midrange magic of the EL34s. The KT88s have an obvious power and punch advantage and are more revealing and precise but that midrange magic is missing so I keep going back to the EL34s.

Good Luck and Great Listening!