With Capella's Double choc you're somewhere in between which is perfect for me. I like a little dark choc taste. The creams help smoothen the chocolate, the marshmallow offers sweetening and also the kind of texture I expect from the actual bar. Bounty bars have a dry-sweet cream, coconut filling, vanillas or custards don't fit. Also, the coconut-cream filling takes up over 1/3 of the actual bar, so should be the prominent ingredient.
At least a one week steep, to allow the coconut to mellow and blend nicely with the creams.
It's been a while since I mixed this, I say fire ahead with your preferred coconut so long as it's on the sweeter side. If it's something like Inawera drop the % as they can be quite strong - so long as you're not over-powering the chocolate