winter wheels, how small can I go?

[cossie1600]

I have been a holding out on snow tires due to my commute (1.5 miles) two days a week and the cost. I wasn't really planning to get anything unless something extremely cheap comes along. Well today I found a pair of front wheels off a Civic that I think might fit. I dont know what brand they are, but they are 18x8 with a 45mm offset. I am thinking about fitting 225/50/18 on there. Is that okay to fit in the front over the sport caliper? I have used 18x9.5 with 35mm before, not sure if 45mm will make it better or worse. If this works, my fronts should be all set.

Now for the back, can I use 17x8 or something? What can I use to clear the rear brake calipers on the sport package.

I don't care if the rim doesn't match. I only need to get up a steep hill and get to work when necessary. It's a hopeless feeling to have to walk home in the snow.