You're not going to get a lot of deep bass out of any bookshelf (that I know of) with sufficient sensitivity to mate with a <10wpc 300B amp. I used a pair of 3a deCapo (large-ish) monitors successfully with a pair of Cary 300B monos. Dynamics are somewhat limited as is the bottom end, but overall it worked out well.
Good Luck
Marty
Good Luck
Marty