J, when you are thinking of F/I you need to consider some other factors as well. which kind of set up do you want? turbo or supercharger?
with a turbo set up you will need a VB upgrade because of the amount of torque to protect your transmission. with a supercharger depending on what pulley you use you may or may not need it, but it would never hurt to get it anyways...average cost for a VB upgrade would be ~800-1100 (just an estimate).
like cube said, a transmission cooler and oil cooler will help keep your system cool and prevent any over heating or anything like that.
now onto what kind of set up you want..your options are turbo and supercharger...well nitrous too although i dont think any FX's have ventured there yet. turbo will give you a huge TQ boost early in the RPM and really throw you back in your seat...a supercharger like vortech is more of a linear power gain (more power as you rise in the RPM).
if you go turbo, you gotta think about single turbo or twin turbo; even a single turbo, you have to keep the psi down (no more than 8-9psi on a good tune) or you can still blow your motor if the tune isnt right. if you go twin turbo you should have your engine built for more protection and you can also crank up the psi too for more power.
if you go s/c, theres different pulleys/stages to be used. vortech has 3 pullys i believe. the stock one is said to be boring but many members with it like the one in betwee (3.13 i believe). there are also a few different pulley mods you can do to increase the PSI safely.
if you go with one of these two set ups (sorry i know im not mentioning stillen, i am not very familiar with it i guess someone else can talk about it), you gotta think of supporting mods. a turbo set up you need to decide if you want your downpipe to be catted or catless, catless giving more power but its like a test pipe so it will smell. with twins and vortech you can/should get either hfc's or test pipes as well as a good breathable exhaust system. why go FI then keep everything else restrictive right?
with a single turbo i think its perferred to have a single exhaust because of the single down pipe, or else a reverse y-pipe has to be made to accommodate your dual exhaust. with twins a good 2.5"-3" exhaust should be fine depending on your power. for vortech again it depends on the power you will be putting down...something simple like a 3" single nismo will be fine, or even 2.25" dual from FI.
theres tons of things when it comes to FI. i wouldnt personally suggest what i would get because you are not me. you need to come up with this one on your own after you read everything. this is a BIG financial decision (and it is in no way shape or form an investment

lol). you should think about the costs (anywhere from lets say 6K-25K) and see if its still something for you.