My question is not which FX camera is "the best", they all seem to have their own strengths, and all seem to be getting some good reviews.

The general question is...

Supppose I want to buy and try lots of old, hi-grade, fully-manual, film lenses from the 60's to the 80's (eBay, garage sales, flea markets etc) for not much money, and have lots of fun shooting them manually on a full-frame digital sensor...

...Which camera offers the richest potential in this regard?

1) NUMBER OF LENSES OUT THERE -- For which camera would I likely find the greatest number of good to excellent quality lenses?

2) EASE OF IMPLEMENTATION / NICE ADAPTERS -- Given that I find plenty of lenses for not much money, which camera would be the easiest and/or most satisfying to shoot with, when an old film lens is mounted?

3) ESPECIALLY THE WIDE LENSES -- I am particularly interested in wide, ultra-wide, and fish-eye lenses -- are the answers any different when this issue is given some priority?

4) If the answer is any one is as good as the other for shooting old lenses, the 5D Mark I looks like a strong candidate, since a nice used model can be had used now for about a thousand. ...Anyone out there been using lots of old lenses on the 5D Mark I, and if so, how is it working out?

Thanks for your input.

.
Two relevant excerpts I have come across at http://photo.net/nikon-camera-forum/00SDZD

"The Canon EOS system [incl 5D] is one of the most adaptable out there - with the right (glassless - no loss in quality at all)) adapter you can use Nikon F (non-Ai, Ai, Ais, D), Olympus Zuiko, Leica R, Pentax M42, Contax/Yashica, and I'm sure a few others. Canon landscape shooters regularly adapt Nikon's 17-35mm lens ... There are only two limitations: NO Autofocus, and Stop-Down metering."

and

"Here's what I currently use on my two EOS bodies.
Contax Zeiss - 28/2.8, 35/2.8, 50/1.4, 85/2.8, 100/2.0, 135/2.8
Leica R - 50/2.0, 60/2.8 macro, 90/2.8, 135/2.8, 180/3.4 APO, 560/6.8
Pentax M42 - 50/1.4, 135/3.5
Olympus OM - 24/2.8, 35/2.8 PC
Vivitar Series 1 90/2.5 with C/Y and M42 mount
Nikkor - 800/5.6 ED
Mamiya 645 - 200/2.8 APO
... I have focus confirm adapters for the Contax Zeiss, Leica R, M42, and Nikon systems and they do work."
Also just found this excellent link, which is directly relevant to my original question:

http://www.bobatkins.com/photography/eosfaq/manual_focus_EOS.html

Thanks