I hate to wee on your camp fire but try £77000 and it isn't alot of money relatively speaking for an integrated course. It is about the norm.
I heard a solution relating to bancs, that you have to pay only part of that money and the other will be gotten from your future salary. How much is this 'part of the money'?
I think you have misunderstood the scheme, like
MANY others. You pay for it and
IF in the incredibly unlikely event you are taken on permanently by
ONLY Easyjet beyond the 6 month 'freebie' period then you will be on a reduced salary and your course costs will be repayed over a bonded period.
As for the subjects, do the best you can without going out of your depth. Maths and Sciences are the best bet.