The one thing you've left out is how you actually feel about him.
If you want a relationship, look at what happened last time, where it went wrong, the strengths, the weeknesses and the quirks, look at what you should be trying to do differently next time.
If you do talk to him with the intention of getting back with him, be honest and open about your feelings, but tell him where you think last time could have gone better, apologise for anything on your lists which is your fault, mention anything you'd want him to do differently and then ask if he feels the same way.
This might be hard in person, but overall it's probably a good idea to keep it personal and face to face. Ideally, you should stand a little further away that you'd normally be comfortable with, as that will put a less confrontational or desperate tone to what you're saying (not that it is either, but we guys are notorious for reading social situations the wrong way).
Lay _all of your cards_ on the table, face up, declare what you have, then see what he's willing to put down.