My Dad turns 80 this year, he went the lightweight route a few years ago with two:
Ruger 77 RL tang version in 257 Roberts
Montana 84M Montana 7mm-08
The 7mm-08 gets carried when he's walking a ways or during bad weather, even whacked a Dall Sheep with it when he was 73. He's never really warmed up to the Ruger.
If he's sitting, he has an Ithaca LSA-65 in 270 that he has the most confidence in and usually goes with him. Not a bad choice either, it's probably in the 7 - 7.5 lb range.
But if you can shoot a Ruger in a WSM off the bench and it weighs 2 lbs less than your other rifles, you can do pretty much what you want! Used Colt Light Rifles would be a good place to look, 30-06 is the most common caliber, and are more budget conscious. Of the rifles you listed, the Kimber would be my choice.
