Those 32's really don't suit car at all ( just my opinion doens't mean anything) id stick with the BBS 108's personally or go back to another black alloy. You could buy my beryerns with new tyres for £700 as I'm selling car soon they would suit your car really well they was well over £1600 few months ago when i got them. Beyern only make wheels for bmw's incase u didn't know there high quality like BBS not reps. http://www.beyernwheels.com/
here's mine you can have for £700
http://www.rimstyle.com/alloywheels/selection/?car_model_id=227&page=3&dia=19
or I've seen these they are same beyern brand but in 18" bargain as well at that price with good width with low offset so will be pushed out nicely without the need for any spacers.
http://www.ebay.co.uk/itm/MINT-SET-OF-18-BMW-BEYERN-STAGGERED-WHEELS-/162102432479?hash=item25be0ed2df:g:SNYAAOSw1DtXDfhB
Remember spacers stress the hub and suspension you will prob get uneven tyre wear to on edges too. Your looking at £50 for hubcentric with new bolts just go to any alloy wheel shop they sell them