The Ref 3a deCapo is a large-ish 92db stand mount that gets to +/- 42 hz with a very flat impedance curve (nom=8 ohm) due to a minimal x-over. Not the last word in dynamics, but it will provide extended bandwidth and a neutral midrange from 5W/ch.
For the flip side of the above, Zingali makes some horn mounted floorstanding loudspeakers that are very dynamic, if a bit less neutral than the deCapo. They also get a little hard at higher spls. You can check the OS Services (former USA distributor) website to see if he has any on close-out at your price point.
I've used both with the Cary 300B monos and liked each speaker in its own way
Good Luck,
Marty