Running multiple power to the roof racks....

[MudRunnerTD]

I would run the 7 core and a single 50amp (or less) up the snorkel and onto the roof rack. Also an earth strap from the body to your rack. Earth each of the lights to their own mount on the rack.

Only the light bar will need the bigger supply and the big wire will do that. Doing it this way will leave all your relays off the roof. Run the 50 amp to the relay under the bonnet or wherever you have that set up.

Using a gland you could enter the snorkel at the bottom and lay your cables in core flute inside the snorkel the exit the inside back face of the snorkel at the head.

I can't see why you would need to risk putting relays exposed on the roof.