I am looking to buy a double din DVD player for a 2009 Ford Fusion, and not sure which one to get, or from where. I'm on a budget, looking to spend 250-300 for the head unit. I would also need help with a couple speakers. not changing them all out, just either the front or the back. I am not sure which are more important. The equipment needed for the job, and where to buy it. wiring harness, dash kit, antenna adapter, back up camera kit, etc.. also, how much more would it cost to add a navigation system to it?