Unfortunately this is not the place to see loads of cargo planes visiting, if only! However you will see a number of Mail and Newspaper flight's each morning arriving just after 0700 when the airport opens. These have normally all departed by 0800 so an early morning is required to ensure you see them, three-four seems to be the normal number you will see in one morning, a few different visits would be required in order to clear the fleets out I would guess. The Flights are mainly operated with Beech 1900's, and Metro's by a number of different companies including:-
NAYAS Aerotaxis, Serair & Top-Fly.
Other freight flights appear as required, Cygnus did visit with the Dc8's but since the 757's have replaced them they are rare out here, alot of luck required. Swiftair 737F's have also been know to visit.