I enjoy tube rolling, but there are three 12au7 tubes that I keep in a virtual rotation in no particular order: Mullard, Chelmer, and Telefunken. These three are consistently quieter than a lot of other tubes.
I have a small collection of 50s, 60s GE, RCA (clear top in particular) that become noisy with ghosting and microphonics after a fairly short number of hours.
Stick with my three recommended brands and you will be rewarded with stellar sound and stone quiet performance.
My favorite of the three? Tough call, but I really like the Chelmers, and you can't beat the price!