You are right I haven't done the math yet since I don't even know what power amp I'll end up, but from what I'm reading a 2 vrms source (mine is 2.1) should be good with a lot of amps. The other thing I have to work out is impedance matching.
Another gripe with most of the TVCs I see is they are very limited with the number of attenuation steps, and to get something done custom by a company like S&B (doubtful they even sell loose transformers any more) would be big $$$