206 Vs 500
RoToR_V8D your list of roles is wide and varied.
Think about each role carefully and if you actually will need more than one type.
I know that this sounds a long stretch, but bare with me.
I am flying a B206 at the moment and thinking about getting an R44 for some of the work we do. We have trouble filling the B206 when we have couples walk up to do the tourist thing - it's too expensive for a couple to run the B206, but I can sell the flight for the right price in the R44.
If there is a family, or two couples walk up this is easy in the B206. It is all to do with volume. If you are only doing a couple of tourist flights per week, consider an R44. An R44 is just as comfortable for pax as a B206.
The B206 suits our needs for filming and other AWK (CSIRO surveys, etc.)
If the AWK you are planning is sling related or large load/short hop - go the H500. You can't compare the lifting against the B206.
You mention ENG. Are you fitting a hard camera mount or just a cameraman in a harness. The H500 is a more stable a/c over the 206, but how much work is there of this type? Remember the reduced VNE in the B206 when doors are off.
My own opinion is that the H500 is not a pax aircraft. Even for AWK, the working pax get tired of them unless in the front seat.
If you have hugh volume of tourists, lots of variety in AWK, then go AS350, just ensure that you have maintenance support.
Good luck and if you need a driver with time on all types mentioned...