I take 928 flats which are 52.3mm offsets and have a machine shop cut the 'holes' out to match the 951 turbo wheels. You also get a factory forged alloy wheel that is really strong - I have yet to bend one after 4 years, and they are not super heavy. You can get 928 flats for about $50 a piece. I run 16 x 7's with 225's on the front and 245's on the rear. Here is a before and after picture(s).
mark