Ooh, I forgot that about the low input, despite being a former JMP 2204 owner.
IIRC Cam's is modded in some way, though. As far as current production preamp tubes, the Mullard and Tung-Sol reissues are good stuff. I actually like the JJs in Marshall-flavored amps to darken/fatten them up, but they are definitely higher gain. 12AT7s or 5751s (Dan- newholland- swears by the latter) are an alternative on the front end for less gain. Decent NOS 12AT7s can still be had cheap-ish.
I'm betting Winged C EL34s is going to be a consensus for the power section though, unless you want to put something else (KT77, 6CA7, 5881, etc.) in there. Generally speaking, when dealing with large tube amps, I want the power section to start giving up the goods as early as possible- which is still pretty damn loud; drummer on a good-sized stage level- but my sonic needs may be different. If you just want a cleaner-sounding 800, I'd spearmint with some lower-gain tubes in the front end... And the Winged C EL34s are still a good choice for the power section, because an 800 is damned loud.