Pat,
If your career goal is to get to flying large equipment in short time, then Commutair, Great Lakes and Colgan are viable options. You'll certainly get your turbine PIC faster then at MOST regionals. That MAY enable you to speed up you ascent to larger equipment.
However, if corporate culture, good maintenance, good equpiment with decent schedules, pay and quality of life are important then you may think twice about the above companies.
I'm in my late 20s. I value those things stated above more than turbine PIC. I realize I have several more years until I see the left seat. So what. I like where I'm at. By the time I have enough turbine PIC to leave, I may not want to. Either way, I'll be in my early 30s with more than 25 yrs of flying in front of me, and a world of choices. I'm just trying to enjoy my ride.
Do your homework and figure out what you want. Best wishes in your searches.