Ok let me recapitulate. In the uk, as far as all all hospitals or anyone in the medical field is concerned.
All the medical schools are equal, in fact, the application prrocess for foundtion programmes are even blind to prevent bias.Yes I went to UCL before, yes its a good university, but that make absolutely no difference to my medical career nor will me studying at imperial compared to any other medical school make any difference to my career.
While university prestige can be important for other fields (if you wish to go into research, or a handful select picky employers), most just ask for a 2.1, that includes medical schools. In my class there are students that cam from various universities, some are top universities, yes but many are from low ranked universities, and they're thriving at med school.
Please correct your bias towards the so called "high tiered" universities. If you do in fact want to become a doctor for the right reasons, then you should maximise your chances of getting in. That said, I'm not saying you shouldn't have a preference for somewhere, but i'm saying that if your stengths don't match what they are looking for, don't bother apply.
After looking it up, this is what cambridge state in regards to A Level resits:
At Cambridge, students are regularly assessed by examination and there's no opportunity to resit any exams (with the exception of professional qualifying examinations in Medicine and Veterinary Medicine). Therefore, we would be concerned about an applicant who seldom seems to have 'good' days and is retaking large numbers of units, unless this number of retakes was justified by circumstances beyond the applicant’s control and explained in their UCAS reference
I hope you do have some circumstances that explained your original poor A Level results, otherwise i'm sorry to say that applying would be wasting a choice
Here is a link that give inforamtion about medical schools and their resit policy:
http://www.thestudentroom.co.uk/wiki/Medical_School_Resit_PoliciesI said choose for the town, because you will be living there a minimum of 4 years. Do you think lifestyle isn't a factor?