Not sure if you guys have seen this guys thread or not on lgt.com but he had an old thread of his outback on coilovers being super low and he made a walk through of what he done with the guards to make 18x10 fit. Here's his fitment thread
http://legacygt.com/forums/showthread.php/2005-outback-xt-wheel-fitment-included-184130.html?t=184130
it's just a pitty the photos aren't there anymore.
And here is what his outback looked like.
http://legacygt.com/forums/showthread.php/fs-pa-jay-stellatos-subaru-outback-xt-bagged-w-vip-208629.html
I think he has other helpful tips on there too just have to go fishing for it on that massive forum.