The UPS guy dropped off my new wheels today. I bought a set of 18" Borbet Type TS with the Bridgestone Blizzak Q-rated DM-Z3 snow and ice tires. The Borbet was the only 18" wheel sold by Tire Rack that will clear the massive StopTech 6-piston brakes I will be installing in a couple weeks. I also like that the design of the wheel bears a slight resemblance to the factory wheels.
Here's a side-by-side of the winter vs summer wheels:

Borbet Type TS 18" x 8.5" (Left) and Factory SRT8 20" x 9" (Right)
Here's a close-up of the Blizzak tread pattern. I don't expect the SRT8 will handle very well in the dry after I put these on. But at least I'll be able to make it up the hill to my house if I'm caught out in the next snow storm! I have no politicians living on my street, so the road to my house is sanded and plowed last.

Bridgeston Blizzak DM-Z3 snow tires in 235/60QR-18