Vintage Onkyo gear vs Adcom


Looking for some help on the budget upgrade path:

I currently have an Adcom GFP-565 and have been searching for a power amp to do it justice.

In the course of my research I have stumbled upon quite a few Onkyo integrateds from the late 80's--early 90's (a-8800, a-890 to name a couple) that look very appealing.  I have heard the Adcom and also some Onkyo stuff from that era and they seem much closer in performance than I would have guessed.

So my question is this: should I continue to pursue a power amp for the 565 or sell it to purchase one of the high end Onkyo/Integra integrated?

Thanks

84miles
Thanks all for your time and knowledge!  I'll post the purchase/results once the trigger is pulled.
Ended up with a B&K Reference 125.2.  The Adcom, Rotel and Parasound were tempting; but I wanted something a little newer that wouldn't immediately be a candidate for re-capping.  Found the B&K for $325, which was in the same ballpark as the other options.

After giving the B&K a spin I have to say that I am very satisfied with this amp.  Hard to find much info on their stuff but it is well built with power to spare!

Thanks again to everyone who contributed!!!
I've owned a few 535s over the years and they all worked swimmingly, especially the 2nd version with normal binding posts. Later I was deciding which one to keep having bought a used 5300 (85 watts per side into 8 ohms) which is often ignored as a "lessor" Adcom. I compared the 5300 to my last 535 MKII and found that the 5300 sounded better. It lives in my rack for deck speaker use (a pair of KEF Q10s get put in the windows blowing out onto the deck, with my small REL 108 in the window also…al fresco hot tub boogie) and is great…cost about 100 bucks (in mint condition) a couple of years ago.