What is required to be a helicopter pilot with the RAF?

I initially wanted to fly fast jets, only problem is that i am 6ft 6 so i am too tall. I'm sporty and quite academic, do you advise that i join the RAF after 6th form? and what are the height restrictions for helicopter pilots? my dream is to fly chinooks, which as i understand are quite spacious inside. Otherwise i am in perfect health, i have perfect eyesight and good general health... thanks in advance for answers