There is a Ford spoiler that I think is still floating around on Ebay for fairly cheap. As for body, IMHO the SVT front bumper looks great, if not the best on a wagon.
Another option that looks great is the Ford Acc./Focus S2 front lip spoiler for the OEM front bumper. It looks better in person, looks nice/classy. And with that OEM 2000 bumper, filling in the bumper lines really improves the looks.
I have a BRAND NEW, unpainted Ford Racing SVT front bumper kit I am selling for $300. It goes for about $375 normally. This includes the front bumper, fog brackets, fog lights, lower black lip, and lower grille.
I also have a RARE JMS front lip spoiler that fits the OEM front bumper. I am also sell that, and the would look sick on a wagon.
Most of the other body kits are a bit "overdone", and usually hang too low for a MI winter. The only decent one I can think of is the Wings West Wagon lip kit, but I am not sure if those are available anymore.