When I want to roll tubes at reasonable cost, I go to Brent Jessee recording, aka, http://www.audiotubes.com. Here is his 6SN7 page: http://www.audiotubes.com/6sn7.htm. Over the years I've gotten RCA greyglass 6V6GT, mil surplus ultra low noise Philips EL84WA, and many others including RCA 6922, etc. You also might benefit from a conversation with Kevin Deal, proprietor of https://www.upscaleaudio.com/pages/about.
I've had great luck with both of these vendors.
I've had great luck with both of these vendors.