Where to buy NOS 12AX7's?Which ones?

Fellow 'Gonners have said that I should get the tube mod for my new/used Mesa Baron but it was just re-tubed with stock 5881'sand I want to hold off and use 'em for a bit (also short of cash!).But I was told that most bang for the buck roll would be the drivers.Any suggestions which ones and where to get 'em at a price that won't make me faint?How long should they last?Also still taking suggestions on power cords.A number of folks say heavy duty Belden cheapies will do it others have there fave's.Don't know what they sound like but have respect for the Mappleshade/Omega Mikro folks and Hovland and thinking I'd go with one company for all my needs.How about MIT Z-cords?Think that some of the prices out there are BS.I have a pair of german horn loads (Ehodin)now but might get B&W,Audio Physic,Maggies etc so I need wire with bang for buck that isn't specific to to a speaker.Also have SS Mac 712 and might go tube there.Old MIT first generation tube terminators have been suggested.Need lot's of input so don't think me overly neurotic (yeah right!) if you see these same Q's on another thread.
What are 12AX 7 tubes in your Mesa right now, Sovtek? The Sovtek are surprisingly good, and depending on what sound you are after, I could suggest replacements.

What price limit are you setting? Some NOS tubes are getting scarce and very expensive.
Mazda chrome plates (early 60's French military stock) did the trick with my Baron. The Mazda's will run about $50.00 per tube -- a bargain since you'll get 5,000 to 10,000 hours on the input tubes. I also like the Tele's in this amp. Have not tried the 12AX7 Sovteks that Albert mentions, but was surprised at how good the new 6922's that came with my AI Mod3A are. Very much improved over the Sovteks that came with my old Mod3 several years ago. Still not as good as the Siemens that went back in, though.
I second the opinion of Jim. When I had a Mesa Baron I went with the Mazda Chrome Plates. It will be the best $200 you ever spent and will be a much greater improvement than any rolling you do with the power tubes.

You should contact www.upscaleaudio.com