re frame size,
i'm 6ft 2-4ish, I tend to ride an 18 inch frame.
it depends partly on your riding style, i like a frame with a bit of space under me but with a bit of length in the top tube because thats how mountain bikes were when i started riding.
out of the two sizes you've surgested i'd say an 18 but look at 16 inch frames too, sizes differ between manufacturers, specialized for example do 17, 19 and 21 inch frames instead of even numbers.
the best way of choosing the size is to test ride.
the best way to choose from the three bikes you're looking at is to test ride
the one you feel most comfortable and confident on is the one to get.
