Camber kits are useful if you plan to run in some Solo or Autocross events, to get more negative camber and obtain better suspension work in the corners. For everyday street use, a camber kit is not really necessary as the stock suspension is adjustable enough that a proper alignment can fix any camber problems, including those introduced after lowering a car.
Eibach, Intrax, Progress and Sprint all make front camber correction kits. Ingalls and Goldline make front and rear camber corrections kits. RK Sport sells camber adjustment bolts as well.
