Efficient full range floorstanders to match SET

Some more advice please, I am looking for a "last speaker", to match my "last amp" and yes I know everyone says this is my last purchase. This time I mean it, I think.. My problem, I have settled on 2 lowish power integrated amps, a Viva Solista 845 SET integrated that puts out 18 watts and a Lavardin integated at 50 watts, for warm weather duties. Neither are flea powered, but I can forget most of the offerings from mainstream speaker manufacturers, B and W etc. I recognise you also loose out on the deep base and full range dynamic sound of low efficiency speakers and powerfull SS power amps. I happen to like what you get from low power and efficient speakers. I have been using Living Voice Avatars for years and they are excellent, if a tad polite and laid back. I am looking for something more dynamic, perhaps with a wider, deeper soundstage.
My room is 20ft by 20ft, but certainly cluttered. I enjoy many types of music, Singer songwriters, Jazz, Classical and opera. The real challenge for my chosen path seems large scale classical and opera. We all know how magical SET's and 100db horns can be with the female voice or a jazz combo, but sorting out a complex symphonic piece, not so easy. So I need a compact floorstander, preferably that can be used near wall, that can produce a realistic opera chorus with 18 watts, a tall order? The 18 Watts mean I don't have to go for Avantagarde or Beauhorn at 103 dbs, 92 to 97 will do.
There is some information around, in fact an excellent series on SET amps on the 6moon site, but there are so many choices of matching speakers, often from small cottage industry manufacturers. I rather fancy horns, though my size requirements would mean compression horns or hybrids.
My thoughts included Zingali, the new High Efficiency line from Tyler, Reimer, Triangle, Devore, Cain and Cain, but there are so many others. Budget, up to $5000, preferably second hand, any thoughts? thanks