I used 4 guage ,20ft in total + terminals ,came to 35Can. I would make your own kit ,It takes a few hrs to make and install .
These are my connections ,Battery to stock ground point (drivers side ) ,Battery to intake ,intake to fuel rail ,fuel rail to frame bolt ,Stock engine ground to frame (left side )engine to frame right side ,tranny to frame right side .
Everyone has done there grounding different ,as long as the contact is good ,they all shoud work. The whole point of doing this mod is to reduce restance .
The side benifits are ,better idle ,better throttle response ,lower rpms on the highway ,better starting . These are what I have noticed so far . As far as a good thing ,it doesn't hurt ,and its a cheap mod to do .