You need 1 very good watt to drive those speakers. Even Class A, 1-5 watts may remain extremely inefficient but if you you were to take say a 5w PX25 amp, it will burn off 15w x 2 instead of 90w.
Flea watt tube amps are the way to go.
A good class D amp can sound even better and despite being able to make considerably more power, actually draw less power at idle and at any power level the amps mentioned in this post can make. At the same time it can be stone cold to the touch even after running all day. Plus there’s a good chance a class D set of amps would take up less room and would certainly weigh less. Literally no downside.