Mexico to Panama

I am planning with a friend to hike/hitchhike from Mexico to Panama possibly further. I have spent time (7month) between Honduras and Guatemala so am not so worried about the customs, language, or other barriers. The one thing that my friend and I have talked about is carrying our guns with us. I know we are going to be sleeping in jungle hammocks most of the time, probably in the woods/rural areas. So I question how much people will mess with a couple of gringos and wether or not we should have some sort of deterant. With or without them I think we would still go. And does anyone have information about the licences/permits needed to travel inbetween countries carrying a firearm?

Thanks