Hi A.C.,
Just like you I'm going to start at the RCM after the summer! Sure, there are many teachers there, and if you don't anyone it can be hard to decide! Personally I'm going to study with Yonty Solomon. I knew him before I applied, and he's actually the main reason why I'm going to study there. Of course, it's always important to find a good school in a city that you like, but firstly I think you should always go for the teacher.
Anyway, in my opinion Yonty is an amazing teacher, and to be honest, after meeting him I can't imagine that I want to study with anybody else.
Also, I know Kevin Kenners from masterclasses some years ago, and he's a very nice man, enthisiastic and inspiring. But he is, like Yonty, very busy, and he's away much of the time.
My best advice is to contact Andrew Ball (you can find his email address at the RCM webste:
www.rcm.ac.uk), and I'm sure he will do everything he can helping you to find a teacher. He's very kind, and he has helped me a lot.
Looking forward to meeting you in London!