Best tube rolling options for VAC Ren MkIII preamp


I have read most VAC threads on Audiogon and pieced together some information on tube rolling for VAC 300.1a and VAC preamps (Renaissance Mk III is what I own). Was hoping to get in one thread others' experience/POV/advice on what the best tube swapping options have been for their VAC gear, or other high end amps/preamps that take similar tubes (e.g., 12AX7, 12AU7, 6sn7), or if stock tubes from VAC ended up being the best choice. Thanks in advance for any insights. If I'm missing an definitive thread on this pls redirect me.
podeschi
did some swapping this weekend. nothing matches stock tubes for clear clean highs on vac 300.1a. anyone want to buy barely used (1 hour) 2 matched pairs of Ken Rad 6sn7s drop me a line.
Podeschi,

I have some Ken Rads, are they all the same? Can you send me some pics to wiggy924@yahoo.com?
Podeschi,

How can you come to a conclusion on a NOS tube after 1 hour of listening? I guess you don't believe in break-in period? :-):-)
Not on a nos tube. I didnt need more than an hour with stock input tubes to appreciate their sonic character. Unlike components and cables i havent heard much change over time with tubes even my sophia 6sn7 tubes. Maybe my ears are not evolved enough. :-)