Redsky, again, don't want to repeat what others have said but re: choice of uni - look at their websites, there's actually a map of all uni websites at www.scit.wlv.ac.uk/ukinfo/ukmaphtml which takes you to all the websites - might help you find which ones are within in a decent radius.
As for what's good at which uni - THES (Times Higher) website has league tables, or you could ask his school's advice.
Open days are now different compared with 20 years ago - parents are encouraged to go. I work at a uni where on our open days we offer a parents' question and answer session whilst the students go off in a group, and it's always very well attended.
Re: possible support needs - you could contact student support/admissions wherever he's interested in going and ask about support for him when he's there if you think he might have additional needs.
Has he thought about a campus university - where everything is on one site? Lancaster, Essex, Warwick, Loughborough and so on? They're often gentler rural places with more of an emphasis on support and community, but that might not appeal to your son.
There's nothing wrong with sending him to uni with a bag of shopping!