I've been lowered (and autocrossing) for 5 years without a camber kit. Just fix the toe and go! You'll definitely get some camber wear if you do a lot of commuter miles, but regular tire rotation will make tire life pretty livable. If you have asymetrical, directional tires, that doesn't work so well, though.

If its strictly a commuter car, then I'd get the camber kit, otherwise I'd enjoy the added spunk of the negative camber.