am looking at a similar thing/courses and would say edinburgh or kcl if i had a choice of two of those (i might be biased as those are ones i have gotten into as well). depends on where you want to live really as both are good!!!
Where is your first degree from and what class have you got/are you expecting to get?
This may be a determining factor in where you would be most successful and happy.
Edit: I wouldn't suggest Leeds - their taught Masters specialises in Medieval. This I know because I have a place on it.