Audio Research, What tubes work best in Pre-amp

I am currently trying to find out what the best tubes to use in my LS7 would be, Whether NOS or some new type. I Want Huge SOUNDSTAGE with lots of AIR and The best possible Low Freq. Bass authority and control. I know thats a lot to ask from the tube but any Ideas please let me know. The stock tubes(which I am happy with)are 6922 dual triodes, however I would like to see how much more this piece can do so that is why I am looking. And The reason the bass is very important is that I am primarily running analog from phono so obviously the source input is low and causes a slight leaness to the sound at low volume levels. I dont know much about tubes so please tell me ones that fit with no MODIFICATIONS so I do not damage anything, Also are Tube Dampers Suggested and what type? Please tell me where to buy as well and Thanks.
Huge soundstage and bass, Amperex. Lots of high frequency air, tight bass, and transparency, Siemens. Warmth, richness, Telefunken, or Mullard. If you wish to get, as close, to the ideal tube, as you can, try a combination, of the above tubes.
Tube dampers, will not hurt, but it depends, on where your pre, is, and the tubes, as far as if it helps.
I can provide, the tubes.
I have an ARC LS7 powered by aB&K EX-442 200 w dual mono I thought about Mullard or some NOS tubes. Try some the Tube .coms let me know what you find. Whats your amp try solid state power. What speakers do you use?
I completely concur with Fletch. As an ARC REF. 2 MK. 1 owner I run a combination of Siemens, Telefunken and Valvo 6922/7308s. Think of it like you are making a rich sauce. You need a combination of spices (tubes) to get the right taste (balance) to your sauce (pre-amp tonal signiture.) NOS tubes absolutely DESTROY the Russian 6922 ARC uses, plus they last much longer- 4000+ hours. I have to add that Fletch is a GREAT resource for tubes and for straightforward advice. I've bought from several tube vendors, but Fletch glows brighter than them all !!