Tube upgrade/rolling question

Thanks guys fr your inputs. I've ordered a matched pair of JJ 300B's. I should get them them tomorrow and I'll let you know of the results.
I found out that the 6K7 can be interchanged with 6S7, KTW63, NR81, and CV1941 - are any of them more prefferable than others?

Here is the review from Stereophile I was thinking of. It was a follow up from an article titled "In Search of the Perfect 300B". The conclusion of that article, as in pretty much ever one I've ever read, was that the Western Electric is the cream of the crop. However, if you read the follow-up link above, you'll see where the reviewer in this case thought the brand new Svetlana's came very close to the WE's, more so than any other 300B they tested. For whatever that may be worth / YMMV / I have no direct experience with the new Svets.

Zoya - I'm sure the JJ's will improve over the stock Chinese tubes. Don't forget they do take a while to burn-in. Give them a few hundred hours of play time before making a judgment. From the same review I mention, here is what the reviewer had to say about the JJ:

JJ Electronics 300B: $199/pair. As tall as the KR, but not quite as heavy. Gold wire is used for the grid, and the grid supports are supplied with cooling fins (unusual in a 300B). Worked well in both amps. Very good bass—real pressure there—but with a trace of "hollow" coloration in the midbass when used in the AudioNote. Very involving, even euphonic—almost as if trying to make things nicer than real. Quite open, but a very thin veil was noticeable that resulted in a subtle soft-focus effect. Good dynamics, reasonably fine detail, threw a remarkably wide stage with the AudioNote. Lost some control in complex music. Rhythm okay, but rather speedy and not totally relaxed.

Marco

Are the new Western Electric 300b tubes being manufactured and shipped? I have been told that there is a large backorder and that those backorders are not being filled at this time.

Anybody have any idea of pricing on new WE 300b tubes?