There is enough tallent to do something a bit more interesting.

PP 300B maybe? sort of expensive for output valves....

Smaller DH Pentodes maybe? Type 1619 is a 2.5V/2A filament with characteristics resembling a 6V6. Type 1624 is its 807-looking analog.

Hell, 6V6's aren't embarassing. 10k a-a, with U-L taps between 20 and 25%. Rig them as triodes if you wish. 6W6's are another lightly used valve. The 6W6 even comes with respectable looking triode curves in RCA's RC-23 handbook. 6EY6 and 6EV5 are other 6V6 cousins with low demand and relatively low price tags.

Amp building will require high performance OPT's as a primary expense. There are ways around this. Think Homer Simpson's cloning hammock...
regards,
Douglas