I have a lot of faith in AVA products (400R Fet Valve, Synergy 240/3, T8 preamp), so I would bet the Ultravalve is a solid choice. There is one other you might consider. It is a KT88 by Don Sachs ($1895 USD) 60w/ch.
On paper and from emails with Don, I am very impressed with his preamp. I plan to audition his SP14 preamp in August when I will be in his area of British Columbia. I suspect I'll get to listen to his KT88 amp as well.
Good luck and enjoy the journey.
Michael