Help

[TwoGs2533]

I just got a phantom 2 from someone and I took the gimbal off and have been flying it pretty well but now I’m want to get a camera on there and I’m kinda lost. I believe it’s a gimbal for a hero 3 but I guess I’m wanting to upgrade it to put a better camera on or maybe I should just find a hero 3 to test out? Even still if I get a hero 3 I’m not even sure if I have everything I need. It came with a screen and got antennas and all but like I said I’m lost. Any help would be greatly appreciated