You should be fine with PSS rear and PS2 fronts. All it'll do is increase rear grip a bit and so on turn in it will understeer a bit more if you are driving hard. No harm at all, you just need to adjust your driving to suit the tire set up... and your lap times may not be as fast as if you had matching tires.
Under regular street driving you will never notice a difference.
Auto Detailing Enthusiast!