Another consideration is the trim pieces. If you can reuse the grill parts from your current bumper, great. Otherwise, they add a bit to the cost:
http://986forum.com/forums/general-discussions/24402-2002-2003-front-bumper-swap-done.html
If you get an S model bumper, you will probably also want the trim for the center radiator hole.
I have bought two bumper covers from APW using a discount for free shipping and 15% on one, 20% off an the other. (They send discount emails weekly.)
I can never find the part using their normal catalog, but here's the one for a base model:
http://www.********************************************************************************************/sku/Replacement/Bumper_Cover/REPP010304P.html?loc=Front
I got that to my door for under $300 (primed).
It looks like their S model bumper I purchased is no longer available. Part number was: REPP010303P and it cost about the same.