well, the camber kit isn't neccessary in my mind. Your issue is going to be with the 255 in the rear, especially in those specs. You will need to run a higher offset. Another question is how low do you plan to go when you drop it. I am slammed, with a 225 in the rear and still rubbing on big bumps with no one in the car. The camber kit is really not going to help you. If you have the cash, adjustanble a-arms would be the best bet for controlling camber. Check out Megan's, they are nice. The camber kit will also push the wheel out even further stopping you from lowering it. Another unwanted side affect.
hope that helps.