best setup?
Supercharger: harder on your piston rings due to heat and always being on boost at WOT. Also, with the motor being internally stock you have a weak valvespring set that should be upgraded. Superchargers are also highly inefficient after one pass down the track, and they rarely run consistently unless there is a huge aftercooler setup on them. "One pass wonder" comes to mind.
Heads/cam/nitrous: only thing cooler than the sound of a blower is the sound of a car with a lopey idle. Plus, your valvetrain should be safe for abuse due to the better pushrods / springs / valve upgrades. Nitrous is nice because you can use the power whenever you want it and have it off for the rest of the time. Its also very cheap. Keep in mind that if you do not live near any nitrous refill stations that this option might suck and be more of a hassle.
dyno charts? Here is my old setup when I had heads/cam/nitrous. This was about 2 years ago, and I we didn't have any LS6 intakes back then:

Old setup:
MTI Stage 2 heads
MTI T1 cam
MAC headers w/offroad Y
MTI airbox
ASP crank pulley
3" exhaust cutout
dry nitrous kit
Tony <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />


