I won’t speak about styles, as most can be tailored to suit different builds of fighters. I will tell you which things are most vital to a short, strong and explosive fighter: -Overhand right -Low kick -Decide between being a combo fighter trying to wear down and dismantle a guy, or a power puncher looking for a flash-KO -Punching and kicking power -Pressure and ring cutting -Cardio Shotokan (point fighting) and kyokushin (kick-heavy, no hands) will make your mind develop bad reflexes for an actual fight. I’d say focus on boxing and K-1 kickboxing. Spar a lot with guys you trust won’t hurt you, but can keep a moderately high pace with. Look at guys like Robin van Roosmalen and Mike Zambidis for ideas on fighting style and reflexes. Fighting taller guys is my kryptonite. I’m great at keeping distance and fighting long, outpointing guys and countering and moving away. This is because I’m 6’1 and not many guys are taller than me to practice with. In your case, you’ll get used to it in time. Just work on the checklist above is my advice. Good luck.