If you want to cut weight, just pull the subs/amp if its possible before you go to the track. Every 100lbs lost equates to 1/10th reduction on your ET at the drag strip. Taking out the 150lbs of stereo stuff and the spare would be close to 200lbs. Again, thats only if removing the audio equipment isn't too much of a pain in the butt, lol.
As far as S/C choice, it's all about what you want.
Roots and twin screw's are all about the instant boost.
Centri's do build boost, but like 04YellowGT said with gears it comes on quick. I have a buddy with a Vortech blown GT and with 4.10's he sees boost pretty fast. Centri's act more like a turbo in that aspect though.