the ms wheels are not a factory option, so no go on those.
in my searches, besides going custom, the kazera kz-v was the best bet. ~130 a rim, 18.8 lbs, 18x7 +50
on the downside, it seems tirerack has put them on closeout so once they are gone, who knows what people can turn to without spending too much
Scott
07 Mazdaspeed 3