Are the 17" wheels needed to clear big brakes? If not, use a 'normal' size. FWIW, '98-2002 Crown Vic/Marquis came from the factory with 16" wheels to clear their bigger front brakes. Same bolt pattern and neutral offset that our Cats take. Lots of those year Crown Vics/Marquis in the junkyards... Or you can use Ranger/Explorer.
As for 17" steelies, that's '03-up Crown Vic police car wheels, but they have a huge 45mm offset.
Look for some crappy 94-95 Mustang GT "tri-bar" 17" wheels. Almost nobody in the Mustang community wants those, so they can be picked up for maybe $200 for a set, and they will clear 13" Cobra brakes ... depending on what calipers you are using, they may work for you. 17 x 8", +30 offset like the other 8" SN95 wheels:
Yup, the Fusions have high offset wheels, spacers would definitely be required. In that case you may as well start with the 07-up Crown Vic 17" wheels, at least they are designed for a vehicle that is over 3,500 lbs.