Well my first question, I have two decks I am to get for excellent prices they are the Sony CDX-Mp70 and the Pioneer DEH-P840MP, which one do you guys think is the better choice here.

Now onto some noob questions, when installing these decks do I need to run a wire right from the deck to the battery? Or will the wire harnesses take care of all that wiring stuff, Thaks for any help.

- Steve

 

you should be able to just use the harness, and I would go w/ the pioneer.

 

They are about the same. The main difference is ease of use.
Pioneer decks are harder to controll. i.e. buttons do different things in different combinations.