Best way to run wire for non-OEM back up cam?

[terrible]

I finally bought my head unit and back up cam for my 2014 express. I'd like to put my Crux CUB-1 back up cam in the factory location in the tailgate handle. Since mine didn't come with a cam I'll be running the cable clear from the tailgate to the back of the new head unit.

Is there any better, bad or worse way to run the cable? Of course avoiding the exhaust and anything moving but is there a decent harness I can follow along? And what about a penetration into the cab?

Thanks for any help!