From what I've read, spacers give you exact amounts of lift and there isn't a whole lot of "settling" that goes on after they're installed, so 1" front and and 1.5" rear will make the rear 1/2 an inch taller no matter (unless you have fat people sitting in back or a lot of cargo in the trunk).

I'm personally going for downey springs in the back and 2.5" spacers in the front, which should give a balanced 2.5" lift.