I was chatting the other day with a guy who has installed NOs on his 5.7L Hemi Dodge Ram P/U and had nothing but good things to say.
He gave me a few tips - for anyone interested - on "bottling" a 5.7L.
First, he said to go with a ZEX wet kit. He said everything you'd need is in the kit (except having the bottle filled - appx. $65.00). Then he said you'd need to "cool" the spark plugs two steps to prevent detonation, which could seriously damage the pistons.
He also said that once the kit was in (it only operates at WOT), you should use the SuperChip FlashPaq to set the fuel for 87 octane.
He runs his with a 125hp shot, and it hasn't caused him any problems at all.
He was running the 1/4 mi in 14.71 @ 92.34 mph BEFORE the NOs kit,
and 13.43 @ 100.01 mph AFTER the installation.
You can see his truck & details here .

For about 10% of the cost of a supercharger, he's got a comparable hp gain.