Are you going to be racing or just doodling along on a nice afternoon bike ride?
Aero can be a little uncomfortable after a while. Pay attention to how much time you spend in the drops on a road bike.
An aero helmet can be very hot, although the gains are huge in a TT.
Aero wheels can take seconds off a TT race but some aero wheels add more effort to a hill climb.
A lot of this comes down to how much money do you want to spend? Light costs money and Aero costs money.
Look around and you will see that most people go with what they are willing to spend.