This is a big question. Off topic too - But that's okay.
No - After careful consideration I am not going this route. A big part of this is because ASL is pretty deaf community based. Now, this would not be a bad thing. As a matter of fact, I would strongly suggest a mother get involved in it pronto. I've also looked into other avenues such as cued speech. It's not widely used yet.
The main issue is that he's globally developmentally delayed (mental retardation). There arn't enough numbers of children like him in the deaf community. So, a lot of his caretaking and what have you will be in the hearing world.
Now, he has hearing aids (what a pain in the @SS they are). We don't know how well he hears. He isn't talking yet but responds to sounds. What he hear could be equivalent to trying to listen to people talk under water. No way of knowing yet.
So, we are going the route of Total Verbal. Ever so slowly.