top tube lenght with awareness of what kind of cockpit you want to run is your main concern. A 56 TT will feel small for regular riding with a normal bars and a stem thats 80-100mm stem. That said, it might feel ok for what your talking about, with a BMX stem and risers.
I'm guessing a 54 TT will feel kinda shitty, to be honest.
top tube lenght with awareness of what kind of cockpit you want to run is your main concern. A 56 TT will feel small for regular riding with a normal bars and a stem thats 80-100mm stem. That said, it might feel ok for what your talking about, with a BMX stem and risers.
I'm guessing a 54 TT will feel kinda shitty, to be honest.
thats my worthless post of the night.
ride it an see.