Cambridge look at the UMS score of your 3 best AS subjects and take the average. I think the average successful applicant got an average of 95% but don't quote me on that. You can look it up, it's online.
I think you'd have a shot, but no-one can really tell you how likely you are to get in. My advice would be, if you don't have a particular preference for either, to base it on your AS results. If they're stellar, go for Cambridge. If not, Oxford.
Don't be upset if they don't take you, because they get loads of amazing applications and the other unis you mentioned are excellent as well. Good luck