There's a DNA 500 for sale here now for just under three grand. Might be worth asking Steve what he thinks of the 500 versus a modded 225 given your speakers and priorities. Best of luck.
Recommendation for Improvement over McCormack DNA-225
I currently have a McCormack DNA 225 mated with a VTL 2.5 and Line Magnetic 502 DAC powering my Salk Veracity HT3's. I think it sounds really nice but can definitely have some top end harshness, especially at the volumes I like to listen to. I consider the Salk's are fairly power hungry in the low end (as confirmed with Jim Salk), can anyone recommend a SS amp with as much grunt as the McCormack in the range of 2K plus or minus. Sure I would like a Pass or Ayre, but those are way above my price bracket. I've tried Bel Canto Ref1000 mono's and Van Alstine. The DNA had a better mid range presentation and better bottom end than both, no comparison. Any other recommendations shy of the DNA 500, which again is over my price range.