if you dont own a kilo, i suggest you keep your mouth shut.
the 53 will be too big for you. i could explain in depth but i really dont feel like it. just take my word for it. they run big. meaning a 50 is really a 53. a 53 is a 56 and so on. my friend is your height and made the mistake of buying the 53 and thats how i got it. he took a $50 hit selling it to me and went and bought himself another one. im 6', for the record and its only a tad bit too small on me, but i prefer a small bike over a too big bike.
/rant