Best full contact martial arts for me?

Alright, well I want a good full contact martial art. I play a right guard and linebacker in football and Im looking to get into boxing. However, I want a martial art to help me with boxing and in the case of self defence. About me, Im 5'10, 175 lbs, and 13 yo (male). I DO NOT want to go into muay tai boxing. Thank you for all valid answers.