I'm not sure about the pin trading, but I can tell you about the Vinylmation, as I too am addicted to the darn things. The best place to buy them is at D Street in Downtown Disney, as they have the best selection of them, but other stores have them as well, not only in DL, but CA as well. D Street also has a big box that has blind traders. The WOD is also a good place to buy them as well. There are places all over the parks that have places to trade them, some bigger than others. They are so small that they can pack easily into a suitcase, so if the kids want to take them I can't see it being a problem. I had fun trading them last time I was there, and your kids will have alot of fun at it. Have a great trip.