What can I drive w/ the 8wpc Air Tight 300B amp?

Klipsch are a great match with low powered SET amps.

I Agree that the Coincident and Silverlines are big players in your amp type/size. I can't speak for the Coincident sound but I can for the Silverlines: Full bodied, natural, non-fatiguing, engaging but not forcefully, excellent mids, clean but not etchy highs, taught and well extended bottom; will closely mimic your amp's personality. Great value, very easy to live with daily. Well worth seeking out for audition. (FWIW: I don't sell them, just own them). Good luck.

Dr Gizmo said you havent heard what a 300b can do unless you heard one driving sunlight engineering se308 concentrics 104db easy 16ohms

I'll speak up for the coincidents. They are amazing. Very detailed and accurate but not harsh in any way. Full range speakers that aren't monsters in the room. Coincidents make tube rolling easy and fun...

Silverline is not *that* efficient unless you use Alan Yuns own homebrew 300B amp that is heavy as heck, still with loud passages we heard it clip @ his shop.

try diatone P610MA or P610MB mated with a supertweeter.
Thats an affordable way to get that WE/Lowther/Fostex sound.