You might want to check if the procharger is legal for your area. I think it's still California pending, but seeing that your from Lemont Illinois I think your fine. Both Procharger and Vortech are great companies. Your in good hands with whomever you choose. I think the question you should ask is Air-To-Air intercooler (Procharger) or Water-to-Air Intercooler (Vortech).
Kenne Bell, Kenne Bell!
No, If I had to choose a centrifugal, I'd choose Procharger, just cause it seems to me they are the ones always pushing the envelope, trying new things, forcing the other supercharger companies to step it up a notch and not just be lazy.
Plus, procharger was the first to acknowledge the benefits of an intercooler on ANY supercharged application, the other companies denied it for years and kinda b.s.'d the public (didnt want to spend $ on research and development, I suspect), they finally came around and now have "aftercoolers" and other intercooling systems integrated into their kits.
Procharger is king of the centrifugal blowers, IMO.
I like 98 Yeller's suggestion about the kenne bell. You should be able to pick up the intercooler/lower intake (and other items) from an 03 and use the kenne bell. This would probably require a new hood for clearance and more work but would be very nice.
If you want an easy installation the ATI is your choice especially if you get the air-water intercooler from Vortech. With the Vortech you have to relocate the battery and tap your oil pan. Not that difficult if you are good with your hands but more work.
I think in the end, you will make good power with both units but for me the ATI would be less work and less money if you have someone else install it.
Talk to some installers/tuners about fitment and I think you will end up with the vortech. Take a look at how the brackets/ducting lay out on each kit. Those guys at Procharger are on there game at the track for sure, But as far as street kits go Vortech is the only choice. Ask someone like Jimmy V about how long the belt stays on his Procharger???
I have had pretty good luck with my Procharger P1SC. I did the entire install myself, and had a "Pro" do the tune. The car runs great, but it took some work. There are several items that you have to purchase to get it to "Rock Solid" configuration, but it's not rocket science. I have over a 1000 miles on it now, and I love it.
I'm about week away from getting a ATI Procharger - P1SC w/8lb Pulley and 3 Core Intercooler , w/ 42lb injectors, C&L M/A & Power Pipe, Accufab T/Body and Magna Flow Cat back system.
Is there anything else that is a most have, also how tuff was it to do the install....yourself?