Twin screw supercharger will give more torque earlier in the powerband but the centrifugal is much easier to install... looks like peak HP claim is about the same
VF website says 8 hr installation time so the low end of your labor quote would be $150 per hour
Dinan CAI &Throttle body, ESS Tuning TS2, Bimmerbrakes gen3 headers, UUC SSK & DSSR. Achilles oil pump, VAC oil pan baffle
M3 Motor mounts, UUC Trans mounts, Modified clutch style LSD 3.15, TMS front subframe reinforcement, Koni Yellow sports,
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Rotora strut bar, FXR HID conversion, M3 Mirror conversion, BSW stage 1 speakers