mate,w as in a similiar boat to you not so long ago.
First off, definitely get your degree - gives valuable life experience and maturity - makes much more sense to employ a pilot who's 'been around the block' a bit in life as opposed to a wet behind the ears 19 year old who's only just learnt to drive.
Regarding the subjects - and quoting not a little bit from the BA website! - do what you do best and what you'll enjoy. Sounds corny, but you'll find a levels a hell of a drag if you're doing geography when really you want to be learning spanish (and spanish girls are far better looking than geography lasses - believe me!)
Lots of people get hung up on the Maths and Physics importance - and there is something in this. Schemes sometime pop up (e.g. OAT - Thomas Cook, Netjets etc) that ask for them amongst others. Would be a shame to do yourself out of those opportunities at the first hurdle. Or you could do what I did - do what you enjoy at school (I did Maths, English, History) and then fill the gaps by distance learning. I did my Physics A level last year by correspondence - tough but worth it if it ticks a few more boxes.
Eoin