Like these guys said, make damn sure it's the right rotation (clockwise vs counterclockwise) and call vortech to make sure you can get mounting brackets and whatnot. The other things you're going to need...
Hardware!!! Very important and often overlooked part. The wrong hardware can obviously lead to compromised strength and durability, and it can also cause you're belt to be misaligned and you're going to constantly shred $35-$50 belts.
All the piping and rubber elbows/sleeves
Intercooler (not necessary but HIGHLY recommended if you're going past 8-9 lbs of boost)
Some kind of bypass valve
Better MAF
Handheld Tuner, get whatever the person tuning your car uses
Custom Tune, Dyno or Email
Boost/vac gauge, don't get just boost
Wideband A/F, Necessary for email tunes, may not be for dyno tunes
Fuel pressure, not necessary but it's nice to know what your fuel is doing
Higher flowing fuel pump, SVT focus or GT pump (get the Gates fuel line too)
Bigger injectors, probably around 39#-42#
That's all I can think of for now