Vintage tube suggestions

Brent Jessee provides descriptions of each type of tube and their sonic signature... 

http://www.audiotubes.com/12ax7.htm

Mullards are great in bass in the EL34s I run in my highly modified voltage regulated Dyna Stereo 70.  Deep and punchy in Legacy Signature IIIs.   Also, the Mullard 12AX7 I get great bass in a 3rd system with an EAR 864 preamp using the military version CV4004 which is very open and detailed (not bright just balanced with a wide frequency spectrum), totally unlike original Mullards which tend to be very warm sounding.  

I would not recommend   Upscale or McShane.    Only because in my own experience  with both there was some difficulty that marred the transaction.    Not necessary to go into detail.  I'm sure that on some level they both meant well and hundreds of others have fared well.    I would recommend Brent Jesse and Jac Music who is in Europe..   There are other  home body retailers whose names escape me but spending time online and talking with others can bring to light much detail to the average person who would like to find gems out there.   Of primary importance is to be able to trust who you are dealing with.   I have also read about  major scams that have occurred over they years pertaining to fake tubes.   Jac Music web site has  a lot of good info about counterfeit tubes.   I bought a pair of Siemens 12at7 from Jac and very happy with the testing and documentation that was provided.  
I have bought many tubes of ebay as well  although did my research prior to buying and communicated with the seller and paid attention to FIRST IMPRESSIONS .  If communication is sketchy and seller does not seem to be forthright or seems to not want to be bothered why even pursue dealing ? 
As far as 12ax7's go there really are more than a few NOS USA made tubes that would be very similar in performance as the best of what Mullard and Tele have to offer.   For that matter there are NOS US tubes that were actually made by Tele or Mullard and other well known companies back in those years.  There is a ton of of info out there and it takes a lot of research online to find out what is out there and learn all one can about tubes.      I had read once that back in those days it was quite common for major companies to award contracts to other companies like Tele or Mullard and many others as well to produce a run of a particular tube.   So then there would be thousands of say RCA 12ax7's made by Tele and would have the diamond mark on the bottom.    Regardless of what anyone would claim I would never buy a tube purporting to be a TELE without the diamond on the bottom..    Being as I am on a different mission these days I have  not paid much attention to what is going on out there and there may well even be fake Teles out there WITH a diamond bottom.   

You can get vintage EI tubes for the preamp at the Tube Depot. I use them in my CAT and at least in my preamp they sound good and last a long time. They're reasonably priced too.

GE or RCA 5751 triple mica black plates from the early 1950s.  Well below your budget.