I just don't think that you can get someone else to be ready. Unfortunately, you can't control his addiction. You didn't cause it. And you can't cure it.
By bringing him on here, your ability to post without him being able to see you when he wants to will be ruined, and you may not be able to be as honest as a result. So your recovery from codependency, which you've made some small steps on here, will be compromised. It will cut off one more avenue you have to get help for you.
Think carefully before you bring him on here. Some things in your life need to be just about you. Is this one of them?
Love,
KJ