Any hog farm will sell you pigs.
I'm guessing that your state has laws about turning them loose though. Unless you have a fenced in area to shoot them??
Also, get a copy of BOAR HUNTER magazine. There are tons of ads in that magazine where you can get different breeds of wild hogs from all over the world.
Check out this one for example;
www.brutalboarcreations.com
or,
www.tworiversoutdoorclub.com
Those are just a couple that I saw in my old copy of that magazine.
Kev