SUGGEST A TUBE AMP?

Quicksilver makes some nice amps here in the US, they've been in business a very long time and have a great reputation.

My first foray into tubes was a pair of QS 8417 mono's that I mated with Quad 63's; wonderful sound! I sold them three years later for exactly what I paid for them.

Yah, you can convert the old 8417 but then you totally change the character and in my opinion, not for the better. Too bad cuz the 5 tube version was a sweet amp. Actually they were mono's.

And yes, as others have suggested, the Atma-Sphere S-30 would also be a great choice if mated with the right speaker.