If it were me then I would probably upgrade the head unit. I have had enough ok ones to appreciate a good in dash source and I have definitely regretted getting an ok one when I wanted a better one.
I currently use this and give it a thumbs up:
http://www.crutchfield.com/p_500HD14...148bt&skipvs=T
I also have come to like the extra storage that the single din provides with the pocket considering how little storage our cars have in the cabin. Lastly the time correction and eq features that a good source gets you can save $ down the road in processors, crossovers, etc.