PC for AirTight ATM300?

Have an AirTight ATM300 coming (8W SE WE300B-based). I've got a Electraglide Fat Boy sitting around, but trying to gear down with this second system, not in quality, but just trying to get away from inflexible pain-in-the...well, you know what I mean. With that said, doesn't necessarily have to be Discovery flexible either. On sound, dynamics are nice but definetly don't want to sacrefice harmonics. Any psycho AirTight owners out there, or SE amp owners (who are psycho by definition [in a good way...])? Thanks.