I think pretty much all FS9 helos are based on a turbine FM because that is what the default ones use. You could call the engine a type "0" in the cfg if you wanted, but I think it would still fly like a turbine powered chopper.
In a thread I read a while back someone explained all the differences between a helicopter FM based on the jet, turboprop, and, helo-turbine engine types. I think it had to do with what sort of animations were available and how engine sounds worked.
Probably someone else can make more sense out of this than I can.