What Branch of the Military should I join?

I am currently 16 years old in high school. I would like to join the military but I don't know what to join. I don't plan on piloting or operating something on a battleship. I'd like to be some type of ground soldier. I want the trainning on how to fight hand to hand. I absolutly have to say I love sniping. I accually have had and still do a ghillie suit I built and I'm fairly active. I am in good shape about 6 foot 150 lbs. What branch of the military is the hardest for snipers? Also I am willing to get myself into shape to join a spec ops group. How long does Marine Force Recon or Green Beret training take?