I'm looking for white rims with a negative offset that look like this or similar. I don't know if I'm not searching the right thing or what but I can't seem to find a good selection of white rims for my cooper.

 

You have a few options.

Find the rim you want, powdercoat or paint it white, a good shop can remove the finish and redo it for you.

Otherwise you will be limited to the selection of wheels that come in white-

Look for brands that will do a white finish-
O.Z.
Team Dynamics
Rota (Various wheels and sizes)
Sparco
Enkei
Drag wheels
Konig
Work wheels
Stuff on Ebay

Some samples with pics-
http://www.google.com/search?client=safari&rls=en&q=white+wheel+4x100&ie=UTF-8&oe=UTF-8#q=white+wheel+4x100&rls=en&tbm=shop
Tirerack lists these white wheels for the MINI-
http://www.tirerack.com/wheels/resul...rSpecial=false

Outmotoring.com has a few wheels in white-
http://www.outmotoring.com/mini-coop...-pro-race.html