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 Dr. Loomis.  I was thinking either GFA 545 or Rotel 980bx  for power amps.  They are both well reviewed but it seems like there are a lot of techs out there that still support Adcom.  Hard to make these calls without hearing the gear first...
i had the (first generation) 545, which i didn't like as much as the 535 or 555, for whatever reason--if your speakers aren't too demanding you can get a 535 for $125 or so. i've also owned various rotel (and currently using an rb-971 in my office)--my sense is that you'll get better synergy with all adcom, but like you say it's hard to tell without hearing
It’s interesting that there is such a wide array of opinions on the Adcom gear.  I’m currently driving B&W 684’s—so not sure if the 535 is up to task.  I’m sure the 555 is great but that’s a big price jump from the 535 or 545.

Then there is always the option to dump the Adcom pre and go for the Rotel/B&W synergy...
I believe I woulf sell the preamp and purchase a used  integrated of more recent vintage?