To quote midnight cruiser: "Obviously, as there are no passengers are on board, much lower standards are required - you might even be overqualified. Most guys cant get into AA, BA and the like, and are working towards getting a real airline pilot job. As you say, you will have to do lots of manual flying, as only airline cadets with special training are capable of managing the modern flightdecks and automatics."
I am pretty sure that was sarcasm.
There is no telling why some people seem to think that just because we fly cargo we are somehow less qualified or less well trained than the god-like passenger pilots. No telling why some people seem to think that 'cargo pilots' are the entry level pilots of the airline world.
Perhaps Flying tigers can tell us what his motives were in the original post?
To answer the question, the minimum requirements are the same as passenger flying except that you have to be willing to be apart from your family for weeks at a time, fly on the back side of the clock for weeks at a time, stay in crappy hotels for weeks at a time, etc etc....