Have you checked craigslist? I see tons of BMW wheels for sale on there. Many sets of E46 M3 wheels, the OEM 18 inch size, if you would consider those. I use at set of OEM 18 inch wheels with Dunlop M3 snow tires in the winter, works awesome.
2006 M3 ZCP. Interlagos Blue on Dove Grey. 6 speed manual.
Eibach Pro-Kit / Koni externally adjustable F&R shocks / DDM Aluminum Pedals / BMW Performance Short Shift Kit / Clutch Delay Valve (CDV) removed / Painted reflectors / Stealth bulbs / Turner 15mm/10mm front/rear spacers.