I don't really think they mind which subjects you do at GCSE. We were just told to pick what we wanted to do. As long as you have English, Maths, Sciences and a modern language to a high standard then it's fine. If you're interested I got an interview for Oxford (rejected after though) and I have 7A*s (English lit, english lang, maths, core science, additional science, french, graphic design) and 2.5As (history, german, RS short course).