Decide what blower

Why would anyone PLAN to use water/meth on a Vortec kit they hadn't bought yet?

Water/meth for a street Vortec setup is a band-aid. Kinda like, "Oh crap, I want more boost on my already installed kit but have no way to being down the discharge temps".

Since you're in the planning stages, I'd be looking into Vortec's air to water inter-cooler and unless you're totally sold on Vortec (and there's no reason you shouldn't be if that's what you want), I'd also be looking into an ATI Procharger with an air to air inter-cooler (I prefer the self contained oil system and zero maintenance air to air inter-cooler).

Water/meth is relatively high maintenance when compared to an inter-cooler. It can be difficult to get right and once you tune for it, you HAVE to run it. Forget to refill the reservoir one time or end up with a clogged injector nozzle and stomp on the gas.... *poof* game over. I'm totally for running water/meth on superchargers that aren't available for certain power adders or for an already installed kit that needs some intake charge cooking but Vortec and ATI both have inter-cooler kits available and they work quite well.

Yes, you'll be able to run elevated boost levels and timing with a cooler air discharge temp from the blower, REGARDLESS of how that cooler air is achieved.

Either kit will (ATI or Vortec) will be more than capable of block splitting power levels.

Some would disagree but I consider it to be great peace of mind to run a forged crank with blowers like these. Not because the cranks can't handle those power levels but because of the additional stresses on the crank snout from running a tight blower belt.

Not a requirement but definitely worth keeping in mind.