I have a Rogue Tempest integrated running in Triode mode, and with ~ 30 watts output potential with 6550 tubes, I am not lacking for power. I'm sure that I could be happy with less wattage. The Tempest has been a pleasure- The guys at Rogue are TOP SHELF. Best experience I've ever had with a company. Its nice to call with a question or issue and have it answered or addressed by someone that really cares. Most of the time, its the Prez. answering the phone.
Check out the Tempest, it has serious balls, Triode/UL switchable, remote volume, and auto biases tubes (6550/KT88/KT90 recommended, but it will take EL34 as well).
I have had it for 3 years, and the way I jump around between pieces of equipment, that's an incredibly long time.
My friend has an Audion Sterling el34 based amp, about 12 watts, I believe, and it absolutely sings thru his Trentes.