Best Tubes on Market today?


I'd like to upgrade tubes on my Mastersound Compact 845 SET.
I'm getting a loud buzzing noise from both channels at  listening position which I find extremely annoying.
 My current tubes are Shuguang 845C (cheap Chinese electron). Pre amp tubes are Tungsram ECC82 and driver tubes 6SN7 EH. Probably all cheap stock tubes. I Love the the sweet sound but noise level is unacceptable.  Also very audible transformer noise, but I doubt there is a fix for that. Are there other ways to minimize tube/transformer noise?

What are the most reliable aforementioned tubes out there and what is the best place to get them?
Upscale audio seems to have quite a selection. PSVANE was also recommended by some. 
 I would prefer not to spend more than $600 on 845 tubes and hoping for reliable clean sounding tubes all around.    
I also have C2600 preamp with stock tubes. Any advice on those? 
ei001h
You pay your money and you take your chances! I have bought many vintage tubes from different EBay sellers successfuliy. Look for sellers that offer tubes that are tested for shorts, leakage and cathode emissions (important!). This last measurement will give a good idea of a tube's potential life - 100% and down!
Some tube testers will only give a "good" reading - not a numerical value. This usually means at least 50% cathode emissions. Meaning that tube life is at least half of new. Such tubes can be considered quite usable and capable of long service! 
All the vintage 845 tubes I have seen are quite expensive but there are a lot of reasonably priced nos 6sn7 tubes available. The Tube Depot currently has 845 RCA tubes for sale for $1,995 each if you are interested.I  have had good luck and sound from the mid priced Shuguang 845 tubes in my Cary 211 AE amps.