If I were you, I'd just keep riding it out at your regional until you get the offer from your company of choice. It's only a matter of waiting it out. I've given this same advice to the young guys in my Guard unit as well. Keep doing the mil flying, upgrade at your company then wait it out.
If F9, B6 or NK (oh snap!) are your target, then absolutely apply. I would not make the move to any of those though simply to fly bigger metal. If AA, DL, UA, WN (shiiiiit) are what you're aiming for, then 121 PIC time at your regional will be your quickest path. Upgrading to AC/IP (if you aren't already) in your MWS is certainly advisable, but if you want to get to a major ASAP then I would argue your regional is the best bet.