Sounds like a fun project, good luck on it. The LM-317/LM-337 (if I'm recalling those numbers right) are adjustable series pass regulators that can handle around 45V drop from input to output, and about 2A of current with a good heat sink. With a few in series you could have an adjustable B+ supply, and with a few in parallel with the outputs connected together through low (something like an ohm) resistors you could have a regulated filament supply (though you might need to swap the bridge rectifier for a doubler to get the voltage you want).
I've used those regulators for the power supply of my homemade audio amp, and it is remarkable the amount of hum reduction they can achieve....That amp is an output-transformerless design that uses 3 to 4(4 for more power) 6080/6AS7 output tubes per channel....That's in 4.0 surround mode, I switch the unused rear channel outputs to be in parallel with the front channel in stereo mode giving 8 per channel.

If you have problems with line voltage fluctuation causing blooming on your TVs you could use that self regulating CCII transformer and another transformer to step one of it's secondaries up to line voltage (if it does not have a 120V secondary), and use it as a regulating isolation transformer for one of your sets.

You can actually use the good old LM317 (or LM317HV) up to some crazy voltages with a simple trick.

http://www.ti.com/lit/an/snva583/snva583.pdf Explains the details. The voltage and current are basically only limited by the laws of physics, and the specs of your pass transistor. (Fairly sure there's commonly available 800v units that won't break the bank.) If the 317's 1500mA (or LM350's 3000mA) are good enough in the current department, you can simplify things a bit by just stacking some "high voltage" zener diodes in the ground connection of the 317 module. You can get ten-cent 82 volt zeners easy. I'd use the LM317HV and make sure Vin is <= Vout+49V. So if you want a 325 volt B+, you could start with up to 374V and not kill the regulator. By placing ~320V of zeners to float the 317's ground up to the +300V level, and it handles keeping things locked onto 325V from there.