While I respect Jackie Chan as an athletic god, kung-fu master and stunt daredevil I do not really rate him as a very good "actor" outside of his Chinese works.
If he wants to be a superhero he needs to aim for something that relies more on his kind of characteristics. RDJ is perfect for Iron Man, nobody could top him. I mean, a live action Kung Fu Panda would suit Jackie Chan very well, he's that type of actor. I honestly can't think of any hero that Jackie Chan would suit (haha, suit, get it? Supersuit).
Wait, didn't he already have his own superhero thing? Jackie Chan Adventures? That was AWESOME too. Just do that, live action movie Jackie Chan Adventures.
So, after that mental workout I have decided something - Jackie Chan doesn't need to apply for the role of some superhero, he already is one.