Integrated or Separates on a budget

Also, any thoughts on the Arcam A90 or A80 (I know the A90 is likely out of my price range, but maybe not new).

I would stay away from seperates in your price range and look around for a used YBA Integre. 50 very sweet high current beautiful quality watts of the best in its' price range. I owned this baby for 7 years, and it delivered the goods until I needed more goods.

Some very good integrated amps mentioned above.

It seems to me, though, the important criteria of driving two pairs of loudspeakers is being overlooked. Other than using a passive switchbox, which would enable two pairs of speakers to be used one at a time, the only viable solution I have seen presented is the NAD C372. I'd also consider a DENON 380X receiver (3801,3802...380X). No, it's not audiophile, but it'd likely keep up with the NAD, and a Denon offers another option that will drive two pairs of loudspeakers simultaneously.

I like the suggestion of a DAC rather than a new CD player. You can find really good DACs for under $500...CI Audio VDA2, MHDT Lab Paradisea, a couple from Lite Audio. Any of these will improve your CD sound, and you still have the advantage of a changer, or the ability to add a computer source down the road.