I've always had my front shocks set slightly more stiff then the rear of the car. I like fast steering response and a slightly softer rear suspension that rolls a bit so I can feel what its doing but also not sliding around. It Really depends on your driving style, If your good at placing the car while having the back end slide out a little bit ever corner than I'd say keep them even or do what Tim suggested and run the rear slightly more stiff.

If not then I'd keep the front roll stiffness slightly higher so it stays more flat and then soften the rear so it rotates with out loosing grip. (I kept the stock rear bar for this reason.)