I think the M77 is an excellent platform. I have a pretty old one that was passed down to me by my late father. It's gotta be from the early 80's. It's served both of us well. I'm sure its capable of shooting much more accurately than I can! So I recommend it.
I did have one of the other rifles mentioned- Kimber 8400 in 300wsm. It was a beaut. Slide smooth as butter, light, accurate, etc... As nice as it was I ended up trading it because I just never shot it. If I were going to spend over a grand on a bolt action rifle right now it would be probably be some variant of the M700. But that's just because I have my old faithful M77.
I've posted it before but here's a pic of it with my GSR.