I assume your goal would be to get a job offer in the city, yes? If so, prior internship is the single biggest factor in breaking into the finance industry.
If you have prior internships in the field you're thinking of going into, then go with the Oxford brand name.
If you don't have prior internships, I would say go with LSE. It's the uni that supplies the highest number of interns to the city, and looking at the current job market, I reckon an internship is the best you're gonna get.
I'm currently at LSE and have experienced first-hand how recruitment is in a recession market.