A vote for the Viva, they make the Solista SET integrated at 17 Watts and the Aurora Monoblocks, I think at about 24. I use the Solista and it is wonderful, if a little bulky, but so are all SET's. It runs really hot, but sounds remarkable, no warm and woolly tube sound. It's detailed, dynamic, quiet and with that fatigue free sound, SS never seems to quite get(My Pass Labs Aleph 3, excepted). I have heard the Art audio, which was great too, but not at the same time, so I can't really compare. I suspect you won't go far wrong with most of the designs mentioned above.
The other plus, is there are few ruinously NOS tubes to worry about. THe newer 845B and M tubes out of China, seem an improvement, but won't break the bank. I have just recieved a set of 845B's, but have'nt had the chance to use
