One of the best schools for anything, especially psychology, is Oxford and Cambridge. I know bit about the school rankings in the UK, but I'm not familiar with the application process.
Could you attend a top-notch school as a part-time student? I'm not saying this for you, although maybe you could do it, but do they offer part time students some classes? Or just some for people that are bored?
I would love to listen to a professor from Oxford. My history professor had PhD from University of London and he was a smart man. It was a intro. level history most of us needed for a humanities requirement so he didn't delve too deep into the info., but he was one of the best professors I had when he lectured.