77000 actuations wouldn't bother me. This is what I would watch for; the 1D IV is a pro body and may have been used professionaly. Professionally used doesn't mean professionally cared for. It means the guy was getting paid to get the shots. I have watched the pro's at sporting events and they are very rough with their equipment. They use it hard and put it up wet. If you found someone like myself that owned one, and I bet Joel's 1D IV is the same way, we treat our camera's like babies. They may get used hard but the get taken care of because of the investment and pride we have in the camera.

$2500 US would be cheap if you can get it for that.

Nascar Photog 102 by hdnitehawk01, on Flickr

As for wide, when you say that it kind of goes against the grain of how I view mine. I have a 5D II and use it for everything wide. The 1D IV is made and designed for the white lenses. Even its AF system seems to favor those lenses. But if I had to pick a "wide" lens for it I would use the 16-35mm f/2.8L II.