Ok, so after several days of reading this, the 6sn7 lovers thread, and a few other places online, it sounds like I will want the RCA VT-231 grey glass, the TS round plate, and the NU VT-231. The other thing is the Psvane DV-181 T2, but at 170 per matched, pair, I might wait on those. Right now I've just got stock driver tubes, have had those for a long while now, ready to see what the amp can do. I'm using this for PS500s, and if I had one complaint, it would be about the pronounced treble of these cans... As a violinist, I need to retain all the treble I can, for as long as I can. I think that the RCA grey glass might be the best of all worlds? Supposedly has detailed, great bass, with lush mids, slightly recessed treble? That with the Brimar, sounds like theoretically, on paper, should be about as good as I can do without spending mad moneys.
Does all that sound pretty accurate? I'm new at tube rolling, but I think I can only do so much researching before I just need to start hearing tubes for myself. Other driver tube I'd like to try is the Melz 1958, but it is difficult to find those, so I think for now I'll "forget" about them.