By "major 121", I'm assuming that you mean "The Big 6". Which path will get you 1000 TPIC the fastest ? The odds for that favor the regionals. While some ACMI's like ATI, and Southern B737 have quick upgrades, you won't rack up the hours nearly as fast as you would at the regionals.

Some posters have suggested going to a LCC, bypassing the regionals entirely. Your background isn't really competitive for good ACMI's or Big 6, which just might be a good thing for this sector, as they'll keep you longer before you jump to Big 6 company. One suggestion: Have a professional proofread your correspondence with prospective companies. I think you got off on the wrong foot by wanting to persue a regional or ACMI. I think you meant to say pursue. Plenty of guys more qualified than you have likely heard crickets for similar oversights.

Many of the ACMI proponents are confirmed ACMI lifers. Your stated preference for living in a warm climate and getting long blocks of time off makes me think that you just might grow into being a home based ACMI lifer. For some, the home basing is a golden trump card, overriding the long term deficiencies in compensation, retirement, working conditions, and benefits. Odds are that at the Big 4 passenger airlines, you'd spend at least some amount of time commuting to a cold weather base. Purple and Brown are better overall in that respect.

Either way, good luck, enjoy the journey.