The stock speakers will def handle it. However, it is nice to upgrade to better speakers such a some 3 way 6x9s. The problem is that most speakers out there will require modification in some way. I have seen some Alpine and Pioneer 6x9s fit right into the housing with no modification so upgrade to those if you dont want to make risers and that sort of stuff. Otherwise, i would recommend Infinity 3.5s up front and the Infinity Kappa 6x9s. Infinitys get insane loud and have a nice mix of clarity and bass. Heres a site for Infinity if you ever wanted to upgrade.
http://www.infinitysystems.com/caraudio/product.aspx?ProdId='KAPPA693.7I'&Ser=KAP&Cat=MEL