Bwhite,
I'm surprised you can hear differences in Ken Rad 6SN7 of different prints. I've literally handled over 500 of these tubes in my lifetime and can't discern any differences. I'm also surprised you prefer their midrange to Tung Sols. I have always found the KR midrange subpar for a 6SN7.
As for my Supratek (line stage only):
6SN7: I use primarily Tung Sol round plates, although I do swap in Sylvania 6SN7Ws, Raytheon (flat plates), Sylvania VT-231 (also 52 Bad Boys), and RCA grey glass on occassion. I'd skip the CV181/ECC32 if I were you. It's one of those "midrange" only tubes with anemic bass and attenuated highs. Fact is, it was never designed for audio purposes (it's an oscillator tube).
regulator: Visseaux 6L6G or Mullard EL37. While I like what the 350B does for the midrange, they aren't my cup of tea for the rest of the audio spectrum. 6F6 tubes are too lean (and a bit edgy) for my tastes and my system. KT66 didn't float my boat either (bass was subpar, soundstage was collasped).
rectifier: Philips metal base GZ34. Defintely not muddy sounding, and far more open then the later production black base Mullards (which I agree are more lush and syrupy). I've never tried 6106/5Y3 in this position, but I'll give it a shot this weekend. I'm surprised it works well in a circuit designed for GZ34.
Disclaimer: this is all, of course, personal opinion based on my system only. For full disclosure, I should also state that I was (and still kind of am) a tube seller.