Before you go any further, search this forum for "hidden menu". Once you turn off the crap settings it sounds much better.
After that, you have several options. It really depends on how involved you want to get. Me, I wanted plug and play. CM631UD would be the exact plug and play HU for your car. Everything works as it did originally. It too has crap default sound settings, which also can easily be changed once you know where to go.