Aftermarket Wheel Help...

[tompal]

Hey all I'm pretty much set on getting aftermarket wheels for my X3 and I just have some quick questions. I realy know very little about wheels (offset and such) and was wondering if you could give me some help. I pretty much set on going with the Beyern Type Mesh wheel. I want to get either 19" x 9.5 or 20" x 10 (they will be strictly summer wheels by the way), but i'm confused as to what offset I would need to get. All the measurements are listed here http://www.beyernwheels.com/typemesh.html . Could someone just please steer me in the right direction. Thank you so much.

-Tom

ps. also any comments on the quality of the band would be helpful.