What's your academic background? If you struggled with A-levels and needed teachers and parents on your back throughout high school then perhaps think about the school with the best teaching reputation, with plenty of classroom tuition.
If you're the sort of person who can study by themselves, and take to things quite quickly, just do the cats £999 option, study online, and sign up to the oxford question bank. It's what I'm doing when I graduate this summer - mainly because it saves me about £2000 which is a heck of a lot of flying.