Celtic,
I think a lot depends on the area where you'll be located - city v. rural, etc. I think you'll find on the whole, however, that you'll get a lot more sympathy and financial support here (tax credits, carers allowance if you care for him in the home, disability living allowance for him, etc.). It might not be a bad idea to start researching things now. We have two Asperger's Syndrome students in the department where I work who get a lot of help from our Disabilities Office.