Which martial art is better for me to learn?

[Pengyou]

I have just finished studying a course in converstional chinese and will be returning to study the language more formally in August. I would like to take up a martial art but I have been told that some forms are better suited for some types of people than others. Is this true? My main reason for studying is to get exercise, improve my flexibility, concentration and coordination and defend myself if they get too aggressive.

I don't remember the right words to describe body types but I am a relatively slim person (not so light any more) long arms, relatively long legs with not a lot of upper body strength but pretty strong legs. Can someone give me some insight/suggestions?

Thanks in advance.