Why exactly are you considering RWD car?
You live in Phily, you should be able to use public transportation during snow storms (might be an option).
My winter tires also serve as my summer tires and vice versa so I just store them on the car.
I store mine in a pile on the side of the garage.
The RWD Lexus IS350 FSport is the way to go. It comes with the newer 8 speed auto. The AWD comes with an older 6 speed auto.
Discount Tire has my winter tires and wheels. A bargain for swap and storage at $50 per season.