[norsairius]

Rear wheels handle propulsion, but the fronts will still bear the responsibility for steering and braking.

You'll want snow tires at all four corners if you're going to run them at all because you'll want consistent grip or else the car will handle in an awfully strange way in inclement weather.

In general, you'll want to have the same tires all around (regardless of type) for the sake of maintaining consistent grip characteristics so the car will handle more predictably. It's safer for you and others on the road.