Thanks for all the replies guys! Just a bit of clarification, when I said "not a gun guy" I meant not a gun guy like most of us here. He does not have a bunch of guns and does not go out shooting very often. He has been out shooting, dove hunting, and such with me and our other brother especially when we were younger. Most of his shooting was with a shotgun and .22 rifle. He knows his way around a gun and has decent fundamentals.
Also, I did say "live off the land" but also said he is going to be raising livestock and such. He is not going to have to rely on his gun to put meat on the table. This whole adventure is going to be ~1 mile from my parents' house and maybe 15 minutes (by car) from me. He is even in the process of building a few small solar cells to power some real low voltage stuff, I think he is talking about charging his cell phone every few days with it as well. He plans to try to live back there as much as he can, but he is not going to kill/harm himself if things get hairy. And, the land (a little less than 20 acres) is his and is surrounded by a good bit more family land.
One last concern a few seemed to have. Our deer season runs from 8/15 to 1/1. Walking up on deer is not "common" but would not really be anything too extraordinary. Considering the length of the season and that he is going to be growing a fair number of vegetables and such I don't think it is out of the question for him to walk up on a deer. The better approach, though, might be to walk out to the garden with rifle in hand, if nothing is around just put it back in the house and continue with the chores of the day.
Oh yeah, we get some really big rattlesnakes around here. I don't really care how many squirrels and rabbits and mice they eat, a 4 or 5 foot eastern diamondback rattlesnake is better dead methinks. Admittedly, snakes that big don't need the pistol rat shot either, though...
Now, the gun stuff...
I guess I do need to look a little more into the .45 LC. Before this I had never really thought much about shooting deer with a pistol. When I go deer hunting I take a rifle. I will have to take this a little more into consideration. How is ammo availability? I will have to try to get by Wal-Mart and see if they keep it.
A .22 is definitely a good addition for all the reasons mentioned. And, considering how cheap it is to shoot might be the best choice. He won't take a shot with a 22 he shouldn't so I don't think it will cause him to wound a deer or something with it.
I actually have a .357 GP100. I think he has shot it in the past, but cannot remember. I got it for the versatility everyone mentioned, but I have never really considered shooting a deer with it. Of course, I have never really thought about shooting a deer with a pistol at all. I am going to try to get out with him some this weekend and plink a little with it and see what he thinks.
I like the pistol/rifle shooting the same caliber thought. I think it might be a little better to have a rifle round and a pistol. This way we can "cover more bases" so to speak. I realize with everything there is a sacrifice, so we are going to sacrifice the single caliber for the little bit more versatility.
Thanks again for all the replies and insight guys!