King's College London or Queen Mary University of London ?Watch
They're both good universities and it's completely up to you depending on what you would prefer but personally I'd pick Kings because of their overall reputation nationally and internationally.
No worries! And I'm not completely sure on this but I think an MA stands for a Master of Arts qualification whereas an MSc is a Master of Science. It's just a matter of which department you'd like to be associated with. for e.g If your undergrad degree was a science based one, go for the MSc