UK Year 9 - Options Choosing for ASD kids

I am very quickly coming to the Options choosing stage of Year 9 and wondered if there's any advice anyone can give me.  I want to help my son choose Options that he will enjoy but also options that he has a reasonable chance of obtaining qualifications at the end, which will ultimately give him greater choice in terms of work etc.

We have been advised to select a BTEC Vocational Training course which would then limit the options my son can take.  It's hard as he is on the lower end of average ability but I want to get the right balance so that he can succeed.