If you really want to stay in the 91/135 world, I'd go with NetJets for the simple reason that they have a defined set of work rules and pay with a Collective Bargaining Agreement. They are the only one with a Union which may not mean anything to you if you've never had one but it is like having an insurance policy. If something goes wrong, they've got your back. Also, you aren't on call. When you are off- you are off and not required to be contactable.