One thing I would say is that whatever subject your DS studies it should be something he's passionate about or wants to study because he thinks it'll benefit him in trying to get into a chosen field. You might not get many contact hours, but it does take time to study, research and revise so what time should be spent on a subject he chooses. Also, it's worth him looking at the modules each uni offers. No point in studying medieval history when he's interested in say recent wartime history.
DD found it impossible to get a job the first year, but your DS should at least be prepared to do a few hours. The second year, he should be able to get a job with uni if he's on the ball and enquires early.
DD's accommodation cost is at the higher end of the scale and her student loan has always just about covered it (£6700). We give her £400pm towards bills, food, travel, clothes (in her case travel home expensive as she's 300 miles+ from home) when she's away from home (not in the summer). She does have a boyfriend abroad, but has to fund travel there, treats out at uni etc - luckily she got a lock down job and store agreed to keep her on a zero hours contract (not normal for the chain). She also does a couple of 3.5 hour shifts for uni (in same short of job but as a Team Leader so a step up).
I would say we always knew she would strive to go to uni, so half planned for this in terms of not over committing ourselves in past years. Up to you, but I'd review what you can afford to give him, and make it clear that that's the maximum. If he's going to uni, it's part of growing up and also he needs to take on board costs as part of that. One thing that might be worth doing is an xmas job as that means he only has to miss sports for a few weekends, and some stores will offer hours late afternoon/evening.