What I did is this... I daisy chained the grounds, like everyone i think does. When I tried to wire multiple wires into the i-pac, I found it very hard to get and more than one 22 guage wire into the i-pac terminals... So I went with the daisy chain idea for the other wires also.
Basically, just go from sau up on the 4-way to up on the 8-way to the i-pac... It workes perfectly.
Best of luck...