classic sounding 25 watt tube amp

Why not just buy a new Dynaco ST70?

They're back in production through builders such as myself and Bob Latino, and are a real bargain, at under $1000 for a made in the USA product with warranty.

I agree with everything Mrtennis said in his last post.

Steve Leung is a great guy, and his opinion on the Cayin amplifiers is dead on. In almost all cases, modern amplifiers do not offer the type of coloration he is seeking out here, though Pehare's suggestion of the Cary Rocket 88 comes pretty close.

Again, I'd stick with a brand new, bone stock Dynaco ST70. Forego any of the driver board updates, as they will definitely take things in a direction you don't want to go, as will removing the negative feedback loop or going with anything other than 15.6 Ohm resitors on each output tube as the amplifier was originally designed. It sounds like you will be most happy with this amplifier.

Conrad Johnson MV45 is a very good idea. I think it will suit your needs well.