Should I do Boxing or Kickboxing?

Ok, its a simple question but its a hard decision. Me and my brother want to take a self defence course and we are split between boxing and kickboxing. I'm 6'5 250 pounds (im also doing this to get in better shape). I think boxing would be better but my brother of course...disagrees and says kickboxing lol. I think being better at punching and dodging is better then kicking punching and dodging because you have less to worry about and less to train and can concentrate on basicaly one thing....punching lol, and i feel like you learn less of each because you have more to learn but thats just my thought, even though I have really long legs. My brothers reason is in kickboxing they teach you a ground game which would help, but i dont know :l What are your thoughts on this dilema? :D thank you all!