Thanks so much for the reply. Sorry it took so long to get back, but crazy busy doesn't even begin to describe what's going on ( but in a good way ).
When I first posted this question, I was working on martini # 2.5, so the thought process was a bit skewed.
I had totally forgot to figure in the voltage drop across the cathode resistor of the 2A3 and the OPT, so, of course, you are right in that I will have 300+ VDC to play with for the 20B. No problem, as using an IT will still give me plenty of B+ available after splitting dual mono with an RC section for the 20BV4.
BTW, all iron ( except PS ) will be nickel core from Dave Slagle at Intact Audio. So very high quality stuff.
Will be using DC on the filaments, presently leaning towards the Colman regs. I initially leaned towards the Tentlabs because of their ease of implementation, but they oscillated into the tertiary winding of Dave's nickel IT's, and the Colman regs are stable. I've read the thread on current sourced DHT filament heating, so I will tread here very carefully. I read your suggestion for battery supplies in the EML footnotes, but Dave advises that will not work with the tertiary winding on the IT. Bummer. Batteries would have been easy and oh so quiet.
On the input, Dave has new silver winding autoformers for volume control w/ 5 db of gain available. They're still in prototype, but the first pair is mine when available.
They'll be feeding the 20B's.
I'm sure I'll have more questions as this project moves forward.
Appreciate your support and encouragement !!
Thanks, Crazy Bill