Driver tubes

Is there any preference for the three driver tubes in the ST120? In other words, do they need any special attention as far as matching or low noise? I see the center tube is used for both channels. Would it be ideal for the best possible sound to have matching triodes there? I know some people don't pay attention to this sort of thing but I want to get the best performance possible.

I'm more than halfway finished building my ST120. Getting pretty excited here.    

The problem with 5963s is that many of them are highly microphonic.  At least most that I've encountered have been. If you're buying untested tubes then it's best to stick with 5814s or organ-labeled 12AU7s.  If you're buying tubes that are pre-tested for microphonics, however, then this shouldn't be a concern.

Lot of people put rubbers on their tubes before using them ...



(Probably a better way to put that)   

Military grade will usually have the extras that eliminate microphonics. Heavier structure, extra mica, spring loading, etc.

Hadn't really thought about organ tubes as being better in that regard though. Seems reasonable as the lower registers from the big guns could definitely be considered hostile.

As far as what works best, it makes sense to have a well balanced tube in the center, but that's only part of the equation. I'm still playing with combinations - currently using a 1940's RCA triode balanced foil getter 12AU7 in the middle and Sylvania 12BH7a's in the channels. Got plenty other options in my big box o'tubes, but those play well together.