What six forms are good in London?

Hi, so recently I have been looking at different six forms in London and I'm wondering what six forms are good and to which one I should i go to? The A levels I want to do are; physics,maths,biology and chemistry. My dream six form to go to is Ashbourne independent six form college. But it has fees and is really expensive so i cannot go there. So what six forms do you guys recommend in London? I do not mind where in London as I'm willing to even travel more than an hour to get there as long as it is really good. If you are recommending a six form you are going to or went to please tell me what a levels you are doing and what grades you got.

So, which school did you choose for your A Levels?