ARC DSI200 or Bryston 4bsst2 & ARC SP16L

Isn't the DSi200 a class D amp? Not sure you are going to get much warmth with that. An ARC tube pre would work very well with the Bryston amp.

If you are looking to add warmth and dramatically increase your listening enjoyment, you should go with a decent tube amp. The McIntosh MC 275 MK V is a great sounding gutsy tube amp that would sound great with your Dyn's. I owned that Mac amp as well as five models of Dyn speakers all the way up to the C4's. An Audio Research tube amp would be a big step over any of the solid state amps mentioned as well. Don't let stories about Dyn's only working well with high powered ss amps fool you. The worst sounding amp I ever tried with Dyn's was a pair of Simaudio W-6 monoblocks... go figure. Once you try a good tube amp, you'll never be satisfied with solid state IME.

There is a SoundStage review by John Crossett where he compares his LS-17 and 4BSST2 to the DSI200. He describes the DSi200 as more coherent and having a midrange richness, and a definition to the music that the ARC-Bryston couldn’t quite match.

Here is the link. . .
http://www.soundstage.com/equipment/arc_dsi200.htm