What's the long term goal? If you're taking a long term view and trying to be more competitive for SW/UA/AA I'd go the regional path because it's the quickest way to upgrade. The upgrade, then 500 hrs and then 1000 hrs 121 PIC are the next big boxes you can check if you don't get hired sooner.
Your resume has more value with 121 PIC time than it does with 320 FO time at a job that you hope is a stepping stone to your top 3 (UA/SW/AA) for SE Texas.
My guess is the odds are in your favor of getting a call for one of your top 3 before you upgrade at a regional. I'd prepare for three years at a regional but would hope that it's 1 - 1.5 years at the most. Reserve/ANG duty can help with the $$$. It's a grind but if you're in it for the long haul regional/USAFR/ANG is probably the best path to get one of you top choices.