Hey-Hey!!!,
A 15 mA/channel with 20 Hy and 100 uF gives less than a volt of ripple with a 1kV CT plate supply. Combine that with a tube active load and I suspect that a regulated supply is not required. The vlave shunt regulator has cool out the bazooo from a string of 3 0D3's. This will want a HV/unregulated supply of ~600V and that IMO, is pushing it, let alone for entry level.
The 1kV CT can be done quite easily with damper diodes like the 12AX4 or 6AU4 depending on your available filament supply. A delay is needed for an LC like this and dampers are just the ticket. Doesn't glow like an 816 though...
regards,
Douglas
....damn Thrintun!