It depends on what you want to do with the car, If its a street car you drive alot, and redlines around stock 6000 rpm or so, then I would go with Kenne Bell. awesome tq. and power. If its more of a weekend track car, some street use with higher revs, Than I would go with a vortech kit, excellent quality and perfomance, and more boost press on top end.
I'd stick with Vortech. You'll gain power everywhere, not just on top. The Ford Racing kit is a Powerdyne kit with Ford badging. It's got better boost response and pickup when compared to other centrifugal superchargers and is also the quietest of all centrigugal superchargers. But, any more than 9psi you'll start breaking them.
I second the votech also. Check out the kits made avaliable from Andersonfordmotorsport.com Their kits come with everything you need to get it tuned and running safely.
The powerdyne is nice buts its limited as far as performance and reliability. It is alot quieter, doesnt need an oil line tap, and feels smoother... but, it runs out of steam around 9 psi and begins to break itself.
The vortech is noisy whinner, but you cant kill it... at least in my experience you cant. And its capable of far beyond 9psi.
kenne bell no offense but i belive this is one of the few blowers that really add all around power... i do alot of auto-x and you see all the guys with vortec's cut the belt just before they start because they never see the power by gettin the rpm's up. for a street and occasional track visit i'd go kenne bell. dont get me wrong a vortech will actually add more power but where its at is what matters
I bought my powerdyne used for $700. Nearly the complete kit and I love it, for the price I paid. If I were to buy a brand new setup I would go for a vortech, rarely hear of any problems, they make some serious power, and even the low end kits work very well. Boost rules.