In answer to the actual question, I have a friend that flies for the same airline I do who went to Regional Airline Academy in Arizona (Phoenix I think). I'm pretty sure it's 141. He got all licenses and ratings, went through the CRJ course there, and then instructed in the CRJ sim. Never got his CFI but knew that airplane like the back of his hand and has had no problems in training or on the line and we do not work for Mesa or GoJets. Long story short, there are ways to get to the airlines fast and still get a quality regional job.

Just my .02: you can get through training quick but don't be hasty when you decide what regional to go with. Personally, those people I've spoken to that work for Mesa are abused by the company and the quality of life sucks. Not worth it. GoJet pilots are regarded by a lot of pilots in the industry as on the same level as scabs. Definitely not worth it - the last thing you want to do in this industry is start out on the bad list.

If flight instructing is not for you, do try and get some experience such as doing a jet training course. It gives you something to offer the airlines and will give you a taste of what you'll experience in training with a 121 carrier.