Hi
apologies, but with the new uncertainty about border and airport visas, I cannot advise about which borders or airports are still issuing tourist visas on arrival. I know that the regulations have not changed, so border visas SHOULD still be issued to bona fide tourists but just what a particular border official may do on a given day is anyone's guess.
If at all practical, always best to get your visa in Blantyre or in Lilongwe
Mike