it basically comes down too whether you want 1cm more or less seatpost showing than what you've got on your leader, don't worry about the 2cm difference in headtube because different stems and spacers can sort that out, eg: if you're worried the 55 is going to be too high on the headtube, slam the stem and use a stem with a big angle like a deda pista newton, posting a pic of you're current leader should be the easiest way to work it out aesthetically, functionally there's next to nothing between them
it basically comes down too whether you want 1cm more or less seatpost showing than what you've got on your leader, don't worry about the 2cm difference in headtube because different stems and spacers can sort that out, eg: if you're worried the 55 is going to be too high on the headtube, slam the stem and use a stem with a big angle like a deda pista newton, posting a pic of you're current leader should be the easiest way to work it out aesthetically, functionally there's next to nothing between them