The BBC classic designs match well with tube amps. I used to have a pair of Spendor SP1/2Es that I ran with an Image Audio amp with KT88s. It was a great match. These days, in a second system, I have a LSA VT-70 (35 watts/ch with EL34 outputs) into a pair of Spendor LS 4/5 speakers. This is Spendor's latest version of the classic LS 3/5a. The VT-70 is a very good tube amp that does bass amazingly well for a tube amp. I've got a review up in another thread on the forum.
Not all tube amps are the same. I would avoid one that is overly syrupy in the midrange and flabby in the bass, but there are a lot of good options available.