Make sure you are not looking at new versions of these.
Telefunken for clear, cooler, neutral, open and detailed sound.
Mullard for warmer, smoother sound.
Amperex Bugle Boy for warm, open and detailed sound.
Sylvania and GE avoid grey plates.
RCA black plates clear and detailed but can sound pinched.
Etc.
Talk to Kevin at upscaleaudio.com