infodeck,
This may seem a tad obvious and my apologies if you've already been down this road but the first thing to do before spending any large amounts of cash is to get yourself to Gatwick and get a Class One Medical.
Regardless of whether you believe you are medically sound, make sure there aren't any less obvious problems (of which you may not be aware yourself - it would not be the first time) and get that bit of paper in your hand.
Good luck with everything.
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