i was happy with the ported blower, but in the end (after a while) i wanted more power, and didn't want nitrous or a lower pulley. i ended up going with a whipple. even with a mild, mild tune, the whipple will make more power, and have more potential than the ported blower--but its SIGNIFICANTLY more expensive---
blower--$3k
injectors/pumps/mass air--$800
subframes, springs, rear end brace, drag radials--$850
those are the minimal supporting mods for the twinscrew (that are on my car). i'll assume you have a catback and cold air intake.
optional are a throttle body, new clutch, with 26 spline input shaft, and a solid rear--i would avoid level 5 halfshafts but that's just me.
you can see it adds up, but in the end, the car can have a glass-smooth idle, and full driveability.