Mike
Your height will not be the only factor for FJ selection; your buttock-knee length and functional reach of your arms play an important part to name just two. That said, I know some pretty tall FJ guys out there.
Where some (myself included) would praise your desire to fly as your number one priority, there are others who will question your loyalty to the RAF if you have logged interests with the FAA and AAC.
Also, there is the age-old 'officer first, pilot second' view which you will have to answer to. Not sure the statement 'I don't care what I fly just as long as I'm flying' will get you far in this competitive age.
Whether you agree or disagree with what I've said, you would be wise to consider your answers to these before sitting an AFCO interview.
That said, I wish you luck in your pursuit to commit aviation!