Hi Em,
I'm based in London too! it's so hard planning and picking a place from afar without being able to visit... I've been trying to pick a place for months now, my fiance is about to go crazy with me!
That said, I did a lot of research on the Moon Palace, and it sounds really beautiful. I decided against it myself because of the location mostly, and because of how large it is, but I have seen beautiful pictures of ceremonies there, and heard great things, so I don't think you could go wrong there.
But, if you feel like it's not right for you, there are so many different resorts in that area, and a lot of them also get fantastic reviews, so you could look a little bit longer and decide on one that you are comfortable with... Although, maybe you shouldn't listen to me because I still haven't picked one!!