Currently have a pair of zipp404fc. Looking to switch to the enve 3.4 with powertap.

I know they are not as deep as the 404fc. Is there a way to determine the best rim depth for a certain size rider? The enve are lighter so maybe they are faster but will they be as aero or is the difference its worth having the power meter?

Looking to use on a road bike for IMLP. Im 6 foot 215lbs.

Thanks