There are only about 12 wires to swap over to a new units harness and are likely color for color. Even less if some or all of the speakers are driven by external amplifiers, then the RCAs are plug n play. So not a very technical operation. Note that if you have wired remotes, they will become obsolete and need to be replaced, along with their extension cables.
My choice would be the Clarion M608. However, its a little wider and deeper. So measure first.