DO NOT DO IT! Do no get stuck at a crappy 135 cargo job. They promise better pay than the regionals, which might be true sometimes, but when you consider all the sacrifices you will make because of it, it is not worth it.
Most of those companies require a contract for a reason, they can't keep pilots employed. They also pay salary so they can work you to the maximum duty time and not pay a cent extra. You will have to move to some po-dunk town too small for the the big freighters; that's why you're there though. No commercial air service into/out of the airport. Work the back side of the clock 5 days a week which equals about 1.5 days off on the weekend. Flying broken planes all the time in the crappiest weather, praying your HSI or and radios will work for that approach down to mins. I've aged 10 years in 1.5 years. Girlfriend left because I never see her, always in a pissy mood, and look like sh*T all the time.
The bottom line, it's just not worth it. People say the best passengers are boxes, but I'd gladly deal with bitchy people who will forget you in 5 minutes, in order to stay alive and have a halfway decent schedule. Hope this helps!