It depends what you mean by two tone......
If you mean different body and roof colour.... the MINI One Conv only comes with a black hood, but on the Cooper and S you can choose a black/blue/green hood at no cost.... Mine is a Cool Blue Cooper with Blue Hood
If you are talking about the new flip paint options... as far as I am aware these are available on any model. You order the car in black, and then clearcoats are applied by the dealer creating an awesome paint effect.... just don't strach it.... this paint option is around three grand.....
More info on the new flip paint colours here.......
http://www.mini2.com/news/news.php?id=243
Jon.