A word of warning. I would not serve pineapple. Lots of people have severe reactions to pineapple and at 6 or 7 years old that allergy may not have been discovered by all families. My husband is a huge fan of the Stitch breakfast at the Polynesian, and I have seen more than one family learn of their child's allergy, nothing like telling someone to take their kid to the ER and not the MK.
For fun "junk" I would probably try the Oriental Trading Company. They have lots of Hawaiian stuff.