As a sidearm to go along with a rifle, it has been my experience that a 1911 is larger size than I like to carry as extra with a rifle, as is a Glock 19 fully loaded. I would suggest a mid frame 38 or 357 in the Ruger speed-six 2-3/4" length, or a Ruger Sp101 2-1/2".
Or... maybe any of the 4" or shorter k frame Smith & Wessons. I like the M-67 idea above as it has a slim bbl and is lite. If you are hunting or hiking, yet not carrying a long rifle, then situation changes as you don't have rifle ammo weight and stock beating against your handgun while slung during walking-so it is more comfortable to carry a 1911 or bigger, but then you may want to opt for a more powerful handgun and can choose from all the magnums or whatever. All of them mentioned will work as a good defense pistol. The Glock is probably the easiest/safest auto to learn in terms of manual of arms. I have some autos and revolvers from big down to 5 shot Ruger SP101, and I find that the 2-3/4" Speed-Six Ruger 357 with it's stock round butt grips (to keep it small) is my favorite carry gun in a Galco leather slide that fits nice on my belt in the front right of my hip. It is short enough to not bother me when I bend down, and it stays out of the way of my rifle when carrying at sling. The larger handguns are too big to be on my belt and stay out of rifle's way.
Good luck choosing!
Last edited by runninmike; 10/29/09.