Getting your CFI tickets in the lower 48 might be cheaper, but getting them in ANC might be advantageous to getting a job. As far as flight schools at MRI, I believe the big one is Land & Sea Aviation, who I believe recently bought Take Flight Alaska. That said, TFA still has its own website. I dunno...... There's also Aero Tech but I don't know their status after the founder passed away a while back. Also check into UAA.
I've had some good friends instruct at the Elmendorf AFB Aero Club and stay pretty busy.
As for the "bush pilot" stuff, I wouldn't discount it if I were you depending on how long you plan on being there. 1,000 hours can usually get you into a 207 with a much better paycheck than instructing and 2 weeks off a month + jumpseats. Just a thought.