757 wannabe
Fleet is currently 22 757, with 3 767 later this year and possibly a further 3 in 2010.
300 flying hours a year is about right, but unfortunately you do an awful lot of duty hours to achieve that. There is a lot of sitting around in freight flying, and the facilities are far from 'stunning', in LEJ and everywhere else.
As for being knackered, it all depends on how you can cope with very irregular sleep patterns. Some do, some don't, it's a very personal thing and you won't know until you try.
In these difficult times, freight flying is arguably about as secure as it gets but be aware that it's anything but 'glamorous'.