How much power needed for Revel Studios?

Great speaker. If you look at their impedence curve they stay above 3 ohms and the curve doesn't have any wild slopes so the speakers can be considered amp friendly. If you read Steophile's review, they were using the Sonic Frontiers Power 3 (a tube amp) with wonderful effect. I've also hear the Studios in a demo using a 150w/c Naim amp (solid state) and they sounded better then any speaker I've ever heard.

One piece of info you didn't include in your question was the size of the room your planning on using. The above demo was in a room about 18x18x8, and we were not close to clipping the Naim.

For the future you might want to rephrase you question to include current considerations. I own Thiels that go down to about 2 Ohms and a 300 w/c amp can have its heart sucked out if it goes into current limiting. Not so the Revels.

I'm powering them with a Pass Labs Aleph 4 (100w/ch, 8 ohms) and they sound wonderful. I would blow up my room (20x25ft) before distortion. The vt200 ought to be more than enough power. You might consider the Pass amp before going to tubes. The Aleph line is a 2 stage Single Ended Triode design, meant to give the natural sound of tubes, but with the speed and slam of ss.

That should work. I have been running my Studios with the SF Power3s which are about 225wpc.