Best place to run power wire...

Depends on what gauge wire you are running. I was able to route the wiring for my aftermarket fogs under to trim panel, behind the door gasket, then trough the hood area along the engine compartment seam.
 
it took me a while to figure out where to run my power cable too, its kind of a pain to get to, but under the passenger side there is a hole in the firewall that comes out right under the battery, it seemed like the best place to run it to me, then you can just pull up the pannel to the side of the seat, and run it under there and to the back. takes a little bit, but worked well, i can try and get you some pics to show ya where