Getting to this party late, but my experience over the last year is exactly what you are considering doing.
I bought an Elekit 300B amp already built (the 8600S with Lundahl transformers and Mundorf Supreme coupling capacitors) to try on a lark. At that point I had Wilson Sabrina speakers driven by a Modwright KWA 150SE amp (150 watts into 8 ohms). Tried the Elekit amp with the Sabrinas, knowing this was a mismatch, and was blown away by the sound.
Thus the quest continued. At this point I now have two SET systems. One with Spatial Audio X3 speakers (97 dB sensitivity) driven by an Aric Audio 300B SET amp, and one with Charney Audio Maestro speakers with Voxativ AC-2.6 full range drivers (98 dB sensitivity) driven by an Air Tight 300B SET amp.
It is important to note, as Ralph alluded to above, that both systems have auxiliary subwoofers. The Spatial X5's have 12" bass drivers with separate on-board Class D amplification, and the Charney Maestros are augmented with two SVS subwoofers crossed over at 100 dB.
But, both systems sound better than any of the many other systems I have put together. Not just in my opinion, but in the opinion of friends who listened to both the current SET systems and my previous higher powered systems. And, no disrespect to Ralph, both systems measure better in my rooms than my previous systems, based on measurements using REW software.
Lastly, although I started with a kit amplifier (which I still have), to my ears both the Aric Audio and Air Tight amplifiers are superior. Of course, the Aric and Air Tight amps were more than twice the price even when purchased used.
So, my advice is go forward! For two reasons: as stated above, because that is what this hobby is all about, but also because you may end up with the best sounding system you have yet to find.
Good luck!
GAR