Need help with 20" wheels, flares, spacers
 

I'm thinking about going with 10" 214's in the front and rear instead of the staggared setup with 10" in the front and 11" in the rear to get a little better traction in the snow (using Yokahama Parada Spec-X tires). Has anyone done this and does anyone know how much spacer I need in the rear to bring the wheel out the same width as the 11" wheels?

Also, does anyone know the part number for the wheel flares?

It will help people get you part numbers if you mention what model year you have. Also, from what I've gathered on this board, narrower tires are recommended for improving traction in the snow.

'07 X5.