The only speaker I have heard with the Cronus Magnum is the Nola Boxer monitor. I thought the two matched quite well. I think they're $1,500/pair w/o stands. Good bass response too even for their size. 90 tube watts is enough to drive nearly every speaker so don't worry too much about speaker sensitivity. With a question like that you'll likely get everyone's favorite speaker for under $2K with very few having actually heard the combo. While the Nola is not my favorite speaker for under $2K I have spent some time listening and enjoying the pair.
As for DAC, I think the best bargain in cheap dacs right now is the Beresford at $279. There are a number of sub $1K dacs I haven't heard yet. But I have directly compared the Beresford to the Oppo 83SE (which competes with $3-4K players) and the little dac kept up with the competition.
Keep us informed!