Even though everything looks covered, Ill put in my two cents, just because Im bored!
If you want to supercharge, the Jackson Racing charger has a good reputation and will get the job done. As someone suggested you can work the blower to be more effecient and prepped for higher boost. For a long time I was planning to do this, but I have now started researching and shopping for turbos.
Now, turning to the Vortech blower. This one is more like a turbo, that still saps power via a belt driven blower. To me, this makes no sense, if you can tolerate lag and non-linear power delivery, then why not get a turbo? (Which incedentally, if designed properly can deliver more effecient power with little lag.) To top it off, last I checked, this kit is even more expensive than the JRSC, which in itself is already pretty costly.
So if you want a supercharger, I think I would stick with the Jackson Racing blower. Otherwise Id go turbo.