Have you tried Allegiant? They are crying out for experienced guys and they don't require a four year degree. They operate the A320, as well as the MD80 and 757. However, it's not a great company and employee relations seem strained.
JetBlue, Virgin America and Spirit will also hire without a four year degree. You're definitely competitive for all three, but you need someone to get your resume in front of the right person.
I did the US regional thing for four years, it's unlike anything else I've ever done in my career and I was ecstatic to leave for a much better job in Europe earlier this year. Avoid it if at all possible.