have you ever heard of a fullrange driver? a single speaker that covers the highs, mids and lows. it has high sensitivity rating, usually in the 95 up so a low power amp can drive it to the fullest. examples are fostex, corals, audio nirvana, etc
just a tip, go to youtube and search for your tube amp (Rapahelite Sinovt) and you will see that these are the kind of speakers that are paired with your amp kahit ibang model nga lang
but this is not to say that you are limited to FR. if you want multidrivers (2-way or 3-way) just look for a pair that has high sensitivity rating para hindi mahirapan ang amp mo
enjoy your stay here