Hi Obct, I can speak with some recent experience about this!
PNG is a land of contrast. In Moresby it is frightening. Don't go outside the airport or your hotel without being accompanied.
While waiting in the airport and plane, there are aroma's you have never smelt before (and never want to again!).
Once in the coastal villages, the locals are very friendly.
But more importantly, you can expect lots of LB friendly waves. They will have a blast. PS. Let me know if you need an equipment list to pack? Reef Booties and a well stocked First Aid/Medicine chest are top of the list. Plus anything to give to the kids like cloths, crayons, paper etc.