Not trying to be a dick, but if you have to ask that question, should you really be giving your friend cycle advice? Did you tell him about AI/PCT? You should just tell your friend to come read these forums for a bit so he knows what he can expect and knows what to do every step of the way.
Edit: Forgot to answer the Q lol. The esters are very similar, so it's basically what ever is available/the better deal.