Best deal going are SVT Focus springs and dampers. You can usually find them dirt cheap. They don't lower the car drastically but they offer a great ride for a daily driver.

I was never a fan of the Eibach springs. Check out Apex and H&R. They offer a more raked look with a bit more of a drop in the front than the back. Every Focus I've seen with Eibach springs looks lower in the rear than in the front...which, in my opinion, doesn't look right.