I'd also check out Brent Jessee at https://www.audiotubes.com/ and Andy Bouwman at https://vintagetubeservices.com/
It's best to call and talk to them as they can better understand your needs. Of course after you've visited their web sites and took the time to see what they may have. It's actually a fun way to educate yourself and have your questions ready for them when you guys talk. Hope this helps.