Well, I am indeed using camber plates but don't know if they are mandatory for this install.
Some more info can be found
HERE in case you have not already seen it.
If you get these just make sure to pre-grease them as they come dry. I don't use a grease gun but prefer to take the centre insert out and grease them fully by hand. This way you get the grease evenly all the way around and you will get zero noise.
They are a bit expensive but if you wait for a sale you can get them at a discount. I paid $249.95 but that was a couple of years ago now.