First Tube amp suggestions

I second the rec for a pre-owned Cayin, specifically the A88T. They sound excellent, are bulletproof, and can run 6550s, KT88s, El34s and even KT120s. They are quieter than some tube amps costing many multiples more. Since the circuit is point-to-point and largely based on the Mac 275, any good tube amp tech should be able to figure out how to service it.  
 

The same candid salesman who turned me onto the Cayin brand (who didn’t sell Cayin at the time) once told me that Jolida (Black Ice) products don’t perform very well. Maybe the newer stuff is much better but his words were the Jolidas “are POS.” FWIW….

Anything made by Quicksilver Audio,

I have owned a lot of their amps, preamps, and they all sound great.

I am not affiliated with them, just a happy user of their equipment.

Amplifiers – Quicksilver Audio

When you just go out and buy an amp, what you have is a compromise constrained by your budget, compatibility, etc.  Those little SET amps have no juice and unless you're running K-horns, will have no head room or depth.  Pbfffttt...

It's a totally different experience when you build a kit amp, like one of the VTA amps.  You get enormous satisfaction from the build and you learn a great deal about operating and maintaining an amp.  You don't get an ounce of that buying a standard commercial product.

With a kit amp, you get to choose what components go into it. Maybe you want to spend a little more on your coupling caps, or any number of other little improvements.  You're much, much more involved in your gear and your system when you build from a kit.  And lest you think it's not as good as a pre-built commercial product, remember that it was designed by a professional audio engineer.  The VTA amps are extremely well thought of and rarely come up on the used market for a reason.

Don Sachs' amp, he's no longer making them, would cost at least $10K if not more. You can find them used for about $2500 I think, and it will smoke most amps under 20K. I use SS, with his DS2 preamp, but were I going to run tubes, it would be his KT88 amp. I believe it runs 55 or 65 watts, less in SE of course it is much lower. This man tricked out Citation and Macintosh gear for years before he began building his own. The transformers are a large part of the magic, no one I know of uses anything as neutral. You would do well to look into them before jumping on anything.