If I were going into a project like this, I would want to make sure it was a success, and therefore I would not want to cut any corners, otherwise it might end up a waste of money.
For me, there are two people who come to mind, Dan Whitelock-Jones in Liverpool, and Martin Garton in Edenfield. Both could build you what you want and it be a very high quality amp.
The Ceriatone amps are actually very good (I've had 5 of them), and you could always order the kit without transformers and source better ones elsewhere. So that's an option, but I doubt either DWJ or Martin would build it for you. Nick at Ceriatone would build it though, and ship it without the transformers which you could get added here. Many options.
Rob