Hi, armglobal....
I was involved in 92 in a similar project,on behalf of a major oil company, but at a much lower scale (initially 2 and then 1 helicopter)
The solution we had found at this time, was to order and buy our Mi (a Mi 8 AMT or Mi 17 AMT for export) at the Ulan Ude (Buriatia/ Siberia) production plan. Then we found a local company to operate it.
Difficulties where many, the first one beeing a very different system of laws from what we knew ( must be more than very carefull here) . Then, rough and inacurate translations, banking procedures, misunderstandings etc...
I this time, the Moscow Mil Design Office, had the monopoly of export sales, usually via the Kazan production plan.
We managed to order and buy this helicopter at Ulan Ude only because of a special dispensation involving the Buratia province.
Something else, make sure the model you want to purchase is actually certified for public passanger use (in this time, only the Mi8 P was certified for public use, the Mi8 AMT was certified for "service passenger and cargo". I believe that the Mi 171 is now passenger certified. these definitions beeing somewhat diffrent from ours)
These certifications, starting from the rivets to aircraft systems are anyway completely different from FAR and JAR requirements...of course.
A team of skilled and specialized lawers is something I would certainly hire if I had to do this again, above all never forget you are dealing with chess game experts.
This apart, this helicopter is really amazing ! perfectly adapted to its fields of operation and the crews were very professional and experienced.
I have already said it on pprune, I would love to fly helicopter again !