Vintage integrated Amps. What to look for?


I am sure there are a few that have done what I am thinking of doing and would like to get some opinions on doing so.

I have for years always had separates, and good ones at that. Now while I have always been happy with what I had I have always had the urge to try some vintage gear.
I thinking of selling my separate preamp and amp and getting an old Fisher, Marantz or Sansui integrated amp. I have read allot of good things on the Sansui 20000.

Who has done this and were you happy with the change?? What were or are your likes and dislikes also what vintage integrated amp's did you look at? consider buying or did buy. I would like to have a phono stage on it.

Thanks
btstrg
I owned the KA=6100 a long time ago. It even drove my (new to me) MG-1s until I could afford a power amp...and Than I turned the Kenwood into just a pre with a snip and a solder.
The volume control was amazing...huge, repeatable and great channel balance thruout its range.
I didn't realize there were so many choices. Started to get a headache looking at all the suggestions. I thought there would be a couple clear cut ones to look at that were at the top but there seems to be more than just a few.
Send me 125$,I'll send you what you need.Sansui 5000.If you dont like it,send it back.BUT,I need to know your speakers,cheers,Bob
Find a mint example, I really like the Pioneer ones. Get it serviced. I have an SA-9500 II integrated, weighs close to 35 lbs and looks fantastic.

Circa 1977, these units are becoming collectable, IMHO.