I think most UK airlines offer a basic salary around £10500 and flight pay of around £2.50 per hour plus commission.
BA and Virgin offer basic plus meal allowances. Meal allowances are worked out according to the hotel menu in local currency. If it costs, say, $30 for dinner in New York then that is what you would be paid if you were there at dinner time.
The danger with this is that is it based on local currency. Therefore, US trips paid in US dollars don't work out to be very much. Sometimes being paid per hour can work out better, depending on the airline.