Welcome to the forum and congrats on a great car.
Definitely don't use the summer performance tires too much longer. Many of us use the OEM rims for dedicated winters. It's the quickest way to prep for winter and gives you time to search the forums and seek out cars to look at to pick better rims. If you're keeping the OEMs for summer, then Tire rack has 17" steelies.
Based on my winters in southern NE, I selected a winter performance tire that is fantastic in all but deep snow.