Recommend upgrade DAC

Currently using Cambridge DAC Magic with SB Duet. Have no real complaints and could happily live with it. But, what would be a nice step up in a DAC for around $800-1000 used? Possibly with HDCD decoding?

Also, all CD's ripped to FLAC. Will ripped HDCD's be recognized by SB Duet and pass them on to DAC?