Forestore,
I don't know if you have any hogs in your neck of the woods, but if it were me, this is what I would do.

Marlin .35 rem.
Great hog gun. Good close range power, and the heavier larger bullets will penetrate well on a hog, and leave a bigger hole on the other side to bleed out of.

Marlin 30-30
Terrific for deer, and it shoots flatter than the .35 rem bullet.

For cowboy shooting, I like your idea of the .45 colt. If you want to carry it deer hunting, I would choose the .44 mag, but why deer hunt with it when you have the two other guns. I think the .45 colt would be a whole lot more fun than the .44 mag, especially if you had the pistol to match.

Dad-gummit, I think I want one now.

C. Davis