Shoreline makes some very fine, but also very expensive (not as expensive as TRL) push-pull 6550/kt88/90 based triodes. Some folks think they are the best of the super power tubes...I couldn't say.
I also remembered the Wavestream Kinetics V-8's...not sure of their power rating but they were designed to drive difficult loads.
I also have a pair of the MFA 200d's (same designer as the V-8's) and they are excellent as well.