I put Pioneer 6x8's in the doors, check my sig for the model. I have the two-ways; there's also a three-way, but I don't know if that changes the size and whether you'd run into problems. Crutchfield seemed to think so, but then again Crutchfield was wrong about my two-ways in the rear doors, too.
My Pioneers pretty much bolted right in with no problems and were a huge improvement in sound over stock.
