National Jet is pretty secure, and they are looking at expansions (apparantly) and growing a few more in the fleet, they also have quite a few bases (more than Skywest I belive), every pilot I have met from NJ has been very happy (tired sometimes, but who isnt on some days)
Pay- No Idea
Skywest, is also a good environment to work in (but I dont know that first or even second hand, it was third hand news)... I dont know much about Skywest