I AM INTERESTED IN MMA AND BJJ. but the most my parents will let me do is BJJ.?

Ok, so i LOVE to fight and everything. i use to only want to do kung fu, but decided that BJJ could help me more, incase i actually got into a fight. My second choice, after finding out that i didnt really want kung fu, was MMA. i DESPERATELY want to do that, but my parents wont let me because they feel it is too dangerous for me. I strongly disagree. but they wont let me do it. so, my dad brought BJJ to my attention, and i took it because it is said to be the closest thing to MMA. none of my cles have started yet, and i cant wait. i am 14 years old, and i feel that i am tough enough to try any martial art, but of course, i dont know if i am tough enough, or skilled to be great in any martial art. compared to all of my friends, my legs are very strong, and i can kick very well (compared to all of my friends). I am tough, and i cant take down pretty good in football. I am very fast, and hold a relay record, and 100 meter run, record, so i am pretty fast, too. I feel that i have good strength, and i work out. I have been working out, and i can tell a huge difference, so i am relatively strong. I thought that MMA would fit me the most, for what i am capable of, NOW. but my parents wont let me. i have thought about kickboxing, and BJJ. but i hear that BJJ is only take downs, and how to keep ur opponent down, and so on. WHAT OTHER MARTIAL ARTS DO YOU THINK I SHOULD TRY FIRST???