I wouldn't let someone else supply meat that I'm competing with. I look for certain things and they're just going to get a box of whatever and hand it out. In the last competition I was in, competitors bought their own meat, but were also given an extra pork butt to cook for the people's choice competition. That seemed fair to me.
So in short, if its your entry, you're better off buying your meat. If its for them to hand out to their attendees or to give to their charity, it should come from them.