not sure what the factory wheel offset on the new legacy is, but wheels that fit older legacys should fit the new one as well. the 2010 retains teh 5x100 bolt pattern. And a check on tirerack.com give a bunch of wheel choices for your car.
4-Time NNJR ESP Season Champion -15 ESP
3rd Place in 09' Pax Championship/Driver of the Year
2012 Northeast Divisional Champion in ESP