Smoothflight
my experience with them is that they are very professional.
They lease a couple of aircraft from Naturelink and they have bases all over the world ie Amman and Kabul to mention a few.
They provide good accomodation.The chief pilot is a bit of a dingbat , I believe.I dont know what they are paying their pilots.
The head office is in New York I believe.
They say that they are a non profit organization I doubt it