FLYJSH has some great advice. I would like to add that the growth of regional airlines has stopped. And may even shrink in the next couple of years. Gone are the days of new airplanes showing up every day. There maybe replacement airframes but that's it.
There will always be a lucky few that will bypass alll the hard work and land a major job with 1000hrs. (Now 1500) but for the rest of us it will entail many many hours of on the job labor to move on. Pick an airline you can be happy with today. Like FLYJSH said, don't commute 3 legs for a quick upgrade.