Mike, you have some good ideas for amps and cables above. While I haven't heard either the Jolida or Primaluna with them, I have Arros and so can comment on how they may perform for you. I've run them on a 6550 based PP amp, and they sing!
Only issue I see is potentially not enough volume before the woofer bottoms out, like Machine says above. The sub will help, but you don't want to run your signal through the subs high pass circuitry as it'll muck up the Arros ability to dig out tiny detail. Your room is probably at the top end of the size the Arros will work in, even with a sub.
As for cables, I'd suggest the Speltz Anti-Cable. The Arro can be incisive to the point of overly bright, so if you go with a tube amp and mellower cables you'll help to avoid the nasties. Don't biwire until you're ready for a change.
Oh, and plug the amp directly into the wall.
Enjoy!