Bro, 21 total sets of leg presses, extensions, leg curls, calf raises, inner and outer thighs...or...10 sets of sumo deadlifts. You make the call.
Less machines, more free weights. Problem solved. Like Fahd mentioned, you can work on your mad crazy jumpz in the weight room. I'd say you can work speed to a certain extent, but only as a byproduct of explosive lifting. Get out on the court or track and get friendly with interval sprinting. Your "quickness" is best worked on the b'ball court, during practices.
Joe Defranco (check the Authors listing, "View All") has an article at his site, something like "15 top exercises for a higher vertical". Take a looksee.