The reason those crew leasing companies don't advertise where the job is specifically located is because they don't want you or their competitors going straight to the principal. Once you contact the recruiter and likely sign a confidentiality agreement, they will disclose the principal to you. A lot of those areas may only have one or two of a specific type, and it isn't hard to figure out who the operator is if you knew the city or in some cases the country.
It's probably a moot point now, but I would put United Aviation, Libya on the list. I had a number of issues with that operation, but the worst was trying to collect my pay and expenses every month. Like I said, if it turns out that the company survives the revolution, it will likely be under new management.
They also used some pilots from a crew leasing outfit that I had heard nothing good about. However those pilots were paid on time and seemed as content as one could be in that environment. I've since worked with that same crew leasing company and had a very positive experience.
I've also been told by a friend who works in Mumbai to stay away from Jupiter, FWIW.