G'day mate.
Sorry about the late reply, havnt been in the Freshwater chat for some time...
Good old Hinchinbrook, one of my favourite spots up here in FNQ, its a magical place. Some BIG Sooties and JP's come out of there mate i can tell you that.
With Hinchinbrook id target the sandy creeks for the Sooties and JP's, it would be perfect for you as your going on a trail, so you will come across some nice streams. I wouldnt worry too much about the salt around Hinchinbrook, thats when you really need a boat and some medium strength tackle.
But from the Info you've given me mate you should pluck some nice fish out of the rivers on some light bass tackle. Take a large variety of lures with you in all sorts of colours, and if you wonder amongst some nice waters, which i must admit are all around the place so they arnt hard to find, then you should do well.
Give us the 'low=down' when you get back mate, dont forget to take the camera aswell
Cheers.
TinarooTriumph