This should be fine since you should run the stickier tire in the rear. And since the PSS has the better traction you are good.
I have run different brands front and back on the track before, and even different sized wheels; so again as long as I kept the high grip in the back, it was not dangerous.
Track / Autocross setup: Forgestar F14 (21.8lbs & 23lbs)
Front: 275/35/18 Continental slick on 18x10, Rear: 305/35/18 RA-1 on 18x11
Drift Setup: Front: 275 Continental slicks, Rear: 255 Michelin PS2 street tire
Laguna Seca previous record - 1:49:498