To be honest, I would not create a hybrid practice of my own. Your bishop's desire is to make Orthodox priests look like Western clergy. So if you are wearing Western clergy outfits because you believe you are supposed to be obedient to his order, then you should not wear a vest because a) you are creating your own custom and b) you would be obeying the letter rather than the spirit of the law.
I personally am scandalized but such a directive, but that's something people have discussed ad nauseum before.
Fr Anastasios
Amen.