2009 GS 2 radio change
 

Hi I have recently bought a 2009 GS2 sportback and I want to switch out the standard stereo for a upgraded one like the gs4 with bluetooth and sat nav. But I have no idea what specs of head unit I should be looking for.

Can I take the head unit from a right off Lancer sportback and is it a straight swap? This seems like a cheaper option that buying an aftermarket head unit.