you can get power from the computers PSU.
as far as the ledwiz depends..
you could just link p1 and p2 leds together.. in this way you only need half as many lines for the lighting..
the pro's to this is you save money on a 2nd ledwiz, 32 control lines go pretty quick when you're doing RGB leds.
the down side is you loose some flexibility in animations.
the happ comp joysticks are 8 way though.. not 4 way.. not sure if they have restrictor plates or what but normally they're 8 way.
for the trackball/spinner you'll need a Opti-Wiz, a keywiz or gp wiz wont work for those.