How are you planning to package them? Are you going to be individually wrapping them anyway? My mother went on a major candy making binge for a while and used the candy melts. As long as she packaged the candies in individual bags (she did a lot of candy on a stick, put it in one of those Wilton candy bags and tied a ribbon on it), it easily lasted for about 2 weeks. It probably would have been fine longer, but by then she got tired of looking at what was left and just threw them together in a big ziplock bag in the pantry where it got bumped around a lot. If you're not planning to individually wrap them, I'd probably use a large Tupperware container, lay them along the bottom so that they aren't touching and put waxed paper between the layers. Try not to jostle them around too much, since they'll get scratched as they come in contact with each other.