I bought a set of BBS CK 18" rims and mounted Staggered standard fit sized Falkens, perhaps overkill on the rims, the opposite for the tyres.
A word of warning, the Falkens took about 500 miles to wear in! They do work well in the snow, but in milder ondifions I was no too happy (I found temperatures had to be around zero before here was any performance improvement over my Michelins PSs, I know this I contrary to the 7 degree rule.
I have run Vredestein Wintrac Extremes on other cars and have been far more impressed with those, with definite performance improvements in temperatures below 7C.
No matter how good or careful a driver, if the temperatures are sub zero, which they're boud to be for a section of the winter at least in all parts of the UK, if you value safety, it's a no brainer, but I always enjoy the nonsensical arguments otherwise!
Anyone want to buy my part worn Falkens!! If I get a reasonable offer I'd change them..... For other winter tyres of course!