The amp seems to be able to drive just about anything, I say that after seeing it do more than okay with a pair of Dynaudio Contour 1.8 recently, and that was a shocker.
I would say using a quality driver or driver set, the choices over 92db with a benign 8Ohm load will yield most excellent results, with the higher the sensitivity rating, the better. The more full range the design, the better. It excels with single driver systems, but is by no means intended for this.
I personally lean toward the idea of using high quality pro-audio drivers with a minimal, or digital crossover. The BMS coaxial compression driver is pretty flat down to 300Hz and 118db,

believe it or not, and coupled with a bass unit like a transmission line that can [easily] go that high, or about any decent sealed unit, you would have a World Class Audio set up that I guarantee would slay most of the shi shi crap that is out there.
www.assistanceaudio.com can make that dream happen.
For more earthly audiophool solutions, the Omega stuff is obvious. The Elegant Solution, less is more, in audio as in nature. The FE-E single drivers are killer values, and they just get better with use, until they are smooth and wonderful. Look also for the Hempsters, now on the way. These are looming large as a godsend for potent digital amps. Use with a nice fast sub and rip. Nothing can touch the little FE127E in its realm. Louis has this one nailed. If you want to roll your own, there are TONS of designs that work incredibly well. Bob Brine's TL's are getting rave reviews. To view the galaxy of single drivers,
www.spectrumaudio.de For inexpensive, excellent high sensitivity designs, look at the Canadian stuff from Axiom Audio, and Athena. Both these outfits are using some pretty high-minded principles, and have access to R&D resources light years beyond usual private sector business models. They also sound great, and their two ways are, subjectively, almost as good as it gets. The little Axiom M40Ti gets my vote for killer inexpensive two way floor speaker, at 92db, ~38Hz.