If you decide to work for NATS, you have to be willing to earn very little in your first 3 years (£10k in year one and £15k in years 2 and 3) and out of that you will need to find accomodation in Bournemouth for the duration of the course. However by the time you have done 16 years you could be earning nearly £90k (if the NATS website is to be believed)
If you go for the RAF, you start on a lot more, and accomodation is provided (although you have to make a small contribution) however the earning potential over your career is diminished. And the sand gets everywhere. Oh and the lift in the extremly tall tower in a hot dusty country doesn't work.