I would recommend the Edelbrock e-Force SC for the 5.7. Their kit upgrades the fuel pump and rails, injectors, etc., and their 50-state legal tune uses only 5 psi with a guarantee against engine damage. It's cheaper on a 6.1 because the fuel pump doesn't need to be upgraded. The other thing I like about it is that it is completely stealth. Fits under the hood, and if you black out the inter-cooler radiator, no one will know it's there, even if they stand right next to the car.
I saw and listened to one installed on a 5.7 at Spring Fest 2 years ago, and that's what convinced me to buy one for my MSRT.