I have a Will Vincent SE45. At 1.75 watts it's a real flea-power amp! It might work well with my vintage Klipsch Heresy's (100 db sensitivity). These would also be a good choice for a 300B amp (Led Zepellin at 7 watts!).
Good monitor speakers for 300B amps.
That is it. Let me know what you think, what you have heard, and what you have used in your system, and don't be afraid to offer an opinion even if you have absolutely no knowledge about the subject.