Not so much an FAA "instructor", but an FAA approved program, I think. Getting that documented after the fact might be difficult. It sounds highly irregular, but I'm not an expert. Most of the larger sim outfits overseas have some FAA certifications ( I see your sim (s) are FAA approved - that's a good sign), and I'm guessing a NZ approved program would be at least similar to a Part 142 type rating program. If your simulator provider has some FAA programs, I'd ask the person who handles FAA stuff your question. He'll at least know who in Oke City to ask about adding the type ratings, and will certainly know if you can be given an FAA approved training/graduation certificate
ex post facto.
The cheap FAA ratings are usually given in 737-200 and -300 sims, so there'd be some adjustment for you. Here's a -200 program ...
http://higherpoweraviation.com/cours...0-type-rating/
and another
http://www.panamacademy.com/boeing-7...aining-courses
It's an interesting question. Marker's path is certainly novel, and just might work if you have the program approvals in hand. Please follow up here with what you find out.