Where did you buy/find the Airport card for this project?

Hi,

I've been looking around Amazon, Newegg, eBay and other sites to find an Airport Extreme Card for this model of MacBook Pro, but I can't seem to find one. The internet is littered with cards from 2008, 2009, and 2011…it's as if my model doesn't even exist. Where did you buy the AirPort card for this project, or where would you recommend finding one?

Thanks.