i have had 9 porsches; now a 2002 C4S.

great car. yes, the S is significantly wider. and so are the tires, so in snow, you may want to find a second, winter, set of tires+wheels. That is what i used to do when i lived in snow country, albany, NY.

gongrats

 

the C4 is fantastic in snow. i've been driving mine in the Chicago winter for 3 years now.
pair of snow tires is a must.
imho, you'll rarely feel the AWD on highways, but mostly in low speeds, when trying to get the car out of the snow (if parked outside).

 

oh, and i would get the newest once you can afford. the 997 interior is way better than the 996, and i hear its mechanically better.