"But I don?t know that I want to move back in there so soon."
This is a smart instinct, there's no hurry is there?
"he needs to go to counselling or some kind of dv program for a while first."
This is a bad idea. Counselling has been shown to make dv abusers worse.
"So I don?t know if he?s going to move in with a friend and I move back into the house or I might find another house nearby to rent for me and DS which he will cover the costs for - he can afford it."
OK this bodes badly. 1) he's engineering it so that you're financially dependent on him by paying for a rented house 2) he's keeping you hanging on his decision about where you will live. He's controlling the situation. You need to take charge.
"She offered it to him on a plate and he took it."
Sorry, but if you believe this tripe I have a bridge to sell you... 
Please take your time, take charge of the accomodation situation yourself, try to disengage yourself from him and get some distance from the situation so you can see it clearly. If he's serious about sorting things out he'll give you space and time. If he's not, he'll pressure you and try to make you dependent on him. Like the cycle of abuse, observe and see how things develop.