Okay, I got the tube fever and should be the proud owner of a Yaqin MS-12B preamp in a few days. I have heard that the stock phone section tubes (12ax7) leave room for improvement. Whats a good way to go, currently don't have the $$ for NOS, so looking at Sovtek, EH, Tung-Sol, etc.

Sovtek LPS is a nice quiet tube.

For new reissuse tubes I have had good luck with Tung-Sol.
I have a pair in my Jolida Amp and a pair of gold pins in my MHZS CD88E CD player.
I tried the Mulllard reissue, but like the original Mullards they tended to roll off on the highs.
Here is an interesting comparison of the 12AX7 done by The Tube Store
http://thetubestore.com/12ax7review.html
In my MS-12B I am currently running a pair of gold pin Ei 12AX7. I doubt if you will be able to find a pair of those though since the factory has been shut down and being reorganized.
For the 12AU7 I am running a pair of NOS tubes. I don't recall what they are at the moment. You shoud be able to find a nice matched pair of old stock 12AU7 tubes for not too much money.

Thanks guys, think i might try the Tung Sol's.