Need help asap - Winter Tires

[kirakira]

It started snowing again in Toronto and I'm starting to panic that my winter tires won't be here in time.

I've been in contact with a garage east of Toronto and they quoted me that the blizzak WS 80 i wanted won't be here until early December. With it snowing more and more often, I don't feel like I can wait that long!

I have decided to take matters into my own hands and have started looking at tirerack and costco to buy the winter tires I want.

I want the Blizzak WS 80, and the garage said that a 225/45/R18 profile will fit my car for all four wheels. I'm new at this car thing as im sure some of you know so could I please ask for your expert advice.

On tirerack it says that the WS 80 225/45/18 has many different sizes, for width and I figure not all the 225/45/18 will fit any 18 inch rims.

What do I specifically need to look for? Is there like a width + length sizing that I need to be aware of before I can order winter tires on my own online?

Please help!