no wireless should be the only rule youll come across. you can use any joystick and gate shape you want. sanwa / seimitsu joystick, and an 8 way gate of course (square, octagon, circle) so you can hit your diagonals.
other than that its just personal preferences and then theres things that give ease of use. you can use any joystick, buttons, gate shape you want. standard for fighting games though is Sanwa JLF with a square gate. so if you use that joystick, you wont have any problems when you have to use someone elses stick. chances are they will have sanwa parts in theirs so youll be familiar with it. sticks like the Eight Arc Fusion are also a good idea because they are multi-console. youll be able to bring it anywhere without having to worry about it not being compatible.
