If you want to use the hottest hellfire motherfucking peppers in the world get those little Vietnamese ones, sometimes known as Ot Hiem(or just Ot with a long "o"). But be warned: if you even touch 'em to your mouth your whole face will feel like you've been hit with a frying pan. It will put you on your ass.
http://www.whiteonricecouple.com/rec...-devil-pepper/
Of course the kids in SE Asia chew 'em like candy, go figure.