Kevin Scott mates his LV with top of the range PARALLEL 300B mono's - using WE glass! That some serious cash we're talking about. But a few things I would say to keep in mind about mating the LV - straight SET 300B will struggle. You need either PP or Parallel 300B ie. about 20watts. Else, it will limit your choice of music.
I personally mate my OBX-R2 with the TEAD Linear A and it works amazingly well BUT it's not a 300B sound at all. It's more of a top end chip amp (47labs et al) sound.
As for 300Bs or SET that I like - try Art Audio for non crazy money. Their 300B PP/parallel are lovely. Kevin sells them for people who can't afford Kondo's.