I would suggest you take the exams first as you are unlikely to get sponsorship from an airfield. Pay varies from airfield to airfield; some pay by the day others by the hour. When fully certificated ie when you pass a competency test at an airfield, £10 - £12/hour is roughly the rate for a 40 hour week. After passing the exams, training will be a minimum of 40 hours of which only 4 hours/day can be counted towards MER (minimum experience requirement) before you can take a competency test at which a CAA Examiner may or may not attend - most airfields get their own local examiner approved by the CAA.