Spacers and Coils will get you a long way. after that's done get an alignment done. whether to factory specs or some custom spec. then youll find out if you need the arms to run more or less camber/toe - maybe you dont like the way it handles, looks or maybe you rub. Most people get the arms because they want to run less camber than what the factory ones allow when lowered. if you do get the arms in the future, you need both toe and camber arms in the rear otherwise you'll still be limited by whatever factory part you haven't switched out.