Good questions. I could probably answer this as a college essay, but I will try to keep it slightly more brief.

What made me choose Shaolin Kung Fu? Simple... I had a teacher when I was younger who I liked and trusted so I went back to him when I was older. When considering studying the martial arts I would encourage you to find a school and teacher that make you feel comfortable more so than I encourage you to choose your favorite martial art.

Granted, knowing the basic differences between the martial arts will help you figure that out a little easier... IE, you probably don't want to sign up for a Brazilian jiu jitsu school if you don't want to roll around on a mat with hardcore guys who want to fight MMA. And conversely you don't want to attend a "hobbyist" school if you want to really train at a physical level and get punched in the face (something I enjoy).

That being said, now that I've learned my system of Kung Fu fairly well I find the Chinese arts to be a good fit for me. My school has a balance of traditional martial arts training - like forms training, but also will allow us to get train hard if we so choose. This way, I receive both the external and internal (inner peace type stuff) benefits of the martial arts.

Training for sleep dep I like to do things that are traditionally known to cultivate discipline, make me more aware of my mind and get me in better shape. This is originally why I started training martial arts again and why I started to a yoga practice. This is also one of the reasons I practice zazen (the seated meditation of zen buddhism).

I like Eastern philosophy because it excels where our western thought lacks. And yes, I think the practice of martial arts makes me a better performer, magician, and person. Another reason I like Shaolin Kung Fu is that it is traditionally practiced as part of a life of enlightenment and it is not just a system to beat people up (though it will do that).

ANY practice that teaches you discipline and helps you enjoy the present moment will help cultivate "inner peace" and "mental stability."

Any follow ups?