I have a AN UK DAC2.1x Sig. I’ve used 6922 Tele gold pins, 6922 Amperex Holland PQ, and 7308 Amperex/Philips SQ.
I doubt you’ll find any true NOS Telefunken. I agree with those who suggested Siemens for sonics similar to Tele’s although they don’t have that slam. You can go the used route and only buy from vendors who publish test results. I’ve had good luck with some Ebay vendors. The days of finding premium NOS tubes for a decent price are over.
Last month I bought a pair of 6922 Amperex D-getters from Brent for $325. That’s about $100 more than a year ago. And I wasn't able to find a pair of 7308's.