I have an 05 LS and am wondering if the disc assemblies from an 07 can be used in rear. I'm sure the knuckles and hubs would also need to be changed. Any input?
I want to put nicer wheels on but don't want to see those big ugly drums

 

Why not just buy new drums and paint them?

I don't mean to be rude, but every major component in the braking system (both front and rear) and many chassis components (both front and rear) are different between 2005-2006 and 2007-2009 models. You'd be better off financially to just trade your 2005 in for a 2007 Equinox.