Hi IE
As you know, I've home educated ds for nearly five years, having removed him from mainstream school in similar circumstances to your son's. He's now 14 and was deregistered just before he turned 10.
It hasn't been perfect but it's given ds the balance he needed to become independent and find a place in the world, which he wouldn't have done had he stayed in school where he was unsupported and uncared for. HE has enabled him to find his strengths and (crucially) it's given me scope to work on his personal development far more than I'd have had time for otherwise. And it's not just the time element either - he was way too stressed to engage after a hard day and simply wasn't capable of learning self-management under those conditions.
He's gained a lot socially because he's been able to learn at his own pace instead of being forced to interact in difficult circumstances. He is independent, travels alone to groups and activities, has friends. He's well liked by adults and unless you knew you wouldn't suspect his diagnoses. He even manages a range of work experience.
Academically he's thrived. We've reduced his curriculum to focus primarily on subjects of interest to him and I've used tutors where he's needed extra help. He has taken one IGCSE (Maths) and is waiting results in two more this month. Plans are he'll take more over the next two years.
He too wants to go to university as he intends to study science - he has considered some fields of interest and we've attended local courses together. I've been looking at college options locally for the past year or so, considering mainstream settings and specialist colleges alike. We're looking at a bridge year at an autism specific college (primarily for personal development/emotional literacy issues) whilst attending a good mainstream college (with learner support) part time as a transition to further academic study. Both colleges have worked together in the past under similar circumstances and see no reason not to accept ds in 2015.
Funding is an issue but the system depends on other colleges not being able to offer the provision he needs, and it looks as though I have that covered. I have just finalised a statement of special needs too, even though he's home educated and he won't get any practical support from it - it documents a history of need that will go towards the colleges continuing to provide for him once he's in their care.
You're wise to start looking at all the options early as you will have time to jump through the relevant hoops to get what you want and need for your son. If you think it would help I'll be happy to talk to you more about our experience of getting to this point.