[isakhnov]

I'm looking to get a set of winter wheels and tires. As I live in Seattle area snow is not the biggest concern but relatively cold and wet environment is.
Based on the data I managed to find online tire choices are
- Michelin Alpin PA4
- Dunlop Winters Sport 3D
- Pirelli Winter Sottozero Serie II

Michelin looks to be the best in case snow is not a problem but it is also the most limited in tire sizes. I'm looking for 18" wheels and I guess my best choice is to go with 245/40r18 on all corners if I stick with Michelin.

Wheel wise I understand that 18x8.5 is the right size for the above tire but I'm lost in the right offset to choose. My understanding is that the offsets should be different between fronts and rears or that I would need to get spacers to get wheels be flush with fenders, is this correct? What would be the right offset to choose (I see 20, 35, 40 etc. listed for various wheels/options). Centerbore is another question I have no understanding on but I assume that I can ignore it as long as the wheel is marked as the right fit for e90/92, correct?

Thanks, Igor