I'm using Musical Concepts modded Hafler 200 series amps and they work very very well. A 280 on the XLs and a 200 on the XLC. You can buy kits or have them do the work. It's a new driver board, larger caps, hexfred diodes, toroid xformer. Any or all of it can me done. They also do upgrades on B and K.
Korato amps drive them well too!
Joe