Better chance at getting in to Oxford Physics or Cambridge Natural Sciences?

Hi TSR, let's get straight into this. School: comprehensive. GCSEs: 12A*. AS: 5A (maths, f maths, physics, chemistry, history). A2: A*A*A*A (maths, f maths, physics, history). Average UMS over AS and A2: 96.2 % (maths f maths physics). Average UMS in A2: 97% (maths further maths physics). It must be noted I expect to do averagely at best at interview. Do I have a better shot at getting into physics at Oxford or Natural Sciences at Cambridge? I was thinking Oxford pros: GCSEs and potential to do well on PAT, reducing pressure of interview. Oxford cons: taking a gap year :/ (Cambridge seem to care less about gap years). Cambridge pros: UMS score. Cambridge cons: my fourth A Level wasn't a science subject.

Surely the question to ask is: would I prefer a straight physics course or a combined science course?