New amp recommendations

just to be contrarian, (unless of course you want to sell it to me) i'd be really reluctant to replace your integra amp--it's a fantastic sounding piece which would cost something like $8k in today's bucks. to be honest, i've only heard it paired with pre-amps of similar vintage (like the integra 308), and i haven't heard it with your (excellent) proacs so i can't recommend a specific modern preamp, but at your budget you can afford to experiment a bit (tubes? passive?). kbarkamian's idea for ARC makes some sense.

What would you think of pairing the integra with an ARC Ref 3? In addition, do you think that Audience AU24 cables could be a good match?
Thanks.

5k in what currency ?? US$ ?? £ ?

Moon integrated in your bracket is worth checking out. Or if you can find one at a discount the Gryphon Atilla .....

Pairing a REF 3 with the Onkyo would be like mounting Walmart tires on a Ferrari.A more balanced approach,consider an Audio Research tube amp at the 2K to 3K price point.

I've found a nice used REF3 for a reasonable price. Should I get it? Also, can you please recommend some good, reasonably priced speaker and IC cables? I've heard good things about Emprical Design cables. Thanks.