ATCO salary will depend on the unit but a 'Tower' only newbie might earn £30k while a fully rated non-NATS ATCO can expect to earn between £40-60k. If they're offering to fund your training, expect a bond...after all, they will be investing nearly £60k in your training. There are 2 UK ATC Colleges, ASTAC at Gloucestershire Airport and BAE Systems in Cwmbran. You'll need a CAA Class One medical too.
If you've successfully passed the interview, you've been offered a gilt-edged opportunity....hope it works out!