The front reinforcement plates are not necessary but gives a piece of mind. Also get:
New FSM's (I only advise this because if/when they do go bad you have to uninstall your entire front suspension and pay for another alignment)
RSM Z3 reinforcement plates
And maybe all new nuts (not necessary but i like to have never been torqued nuts, plus it's cheap)
You could wait on the RSM's. They are easy to replace later down the road and don't require another alignment so I would hold off if they're not bad.
'04 330i ZHP