Min run the regionals. You need to prioritize the mil training and gig. Regional jobs are easier to get these days than hooker cards on Fremont St on a Friday.
RPA gig might help your wallet but won't help you on the way to get to mainline. If I was hot to trot but didn't have the times to be competitive for a hire letter from the main 4 today, I'd trough/bum and dispense with the self-imposed hassle of juggling two de facto part time paychecks.
If you're a non-retiree, you're probably not gonna get picked up in the next 18 months anyways. The name of the game is to survive the paycut long enough for the applicant pool to thin out and make you competitive, without wrecking your long term finances. Personally, if I was a VSPer I'd be shooting at treading water in the Reserves and not expect a mainline number until at least summer 2016, if it were to happen sooner then great.
Now, if you were a d-nozzle in AD and word is out and you find yourself having a tough time getting hired by a unit, then perhaps one should give higher priority to the regional gig. YMMV. Good luck.