It seems like the simple 5-7 spoke steel gray wheels are the only kind that look good on the 6. I've seen some pics in the other forums of some "ass-ugly chromed out bling bling gangsta wheels" and I just think the simple stuff looks hard as nails. The other stuff looks like you're just tryin too hard.
Try here http://www.mazda.co.jp/mazdaspeed/ click on skip to speed up the page load. Then place you pointer over the Japenese text just below the yellow line. The third one will show a list of different cars. Then click on Atenza A-spec. Now you have a few choices click on wheels.