For the USB connector it will be fine on either front of back, but if its in the front it will mean theres a wire comming out and will look a bit messy, alternatively if you dont mind voiding your warranty you can open it up, cut the USB wires, extend them through a hole in the back of the deck and connect a female USB plug, its easy to do but if you need any help feel free to ask me.
Heres a wiring diagram I made quickly;