NAD C 375BEE is highly regarded for about $1500. The 390DD is also a fine (better?) piece but about $2500. Their new digital drive stuff looks very intriguing. I don't think you will go wrong with NAD. LS50s are some awesome speakers, what sub do you plan with them? i am asking because you may want bass management so check that part out.
Main Kef: Reference 205/2 & 202/2c, Surrounds: Kef XQ40, Velodyne Optimum 12, Integra DHC 80.3, Ayre K-5xeMP, Oppo BDP-103, Bryston 4Bsst2, Parasound Halo A31. Second B&W: 685 (3), CCM618, Def Tech Powerfield 1500, Onkyo TX-NR1008, Zone 2 Klipsch AW650.