or put a folder called ssj2gohan in you esf/models/player/
and put a ssj2gohan model in it, and when you start your own server go to advance options and disable the "lock models" option
and when youre in game typ in the console: "model ssj2gohan" and you can play with him
otherwise, do what mystic said, wait for beta 2, and dont ask when its coming out!