J350

Sorry if this has been covered already, but I'm looking at getting winter tires for a 6-speed Touring 350Z & want to know which tire sizes will fit on my stock 18" wheels. I know the stock summer tires are: 225/45-18 up front & 245/45-18 in the rear and Blizzak LM-22s come in the 225/45-18 & 255/45-18, but 245/45-18 should be available soon.
What other tire sizes would work with the stock 18" wheels?
I'm mainly wondering if any of the following 3 scenarios would be advisable:
1) 225/45-18 on all 4 wheels
2) 225/40-18 on all 4
3) 225/40-18 up front & 245/40-18 in the rear

thanks
-J