I agree a good D model is all you need if you working mainly below 5k.
I have worked all of them and rate the Notar very highly , Id look at a 520 with 600 running gear , they are a good rig in the bush.
Don't bother with a C model!
If money wasn't an issue get a F model!! C30 is a great engine. Get some Van Horn blades on when they certified and you'll have an Astar beater
