When you say you want to store it, do you have an estimate of how long? Will you have to re-melt it? If so, I would not consider a metal pan unless you did not want to use a microwave.
When making chocolate for a later date, I use those large disposable Glad containers that have a lid. The one I use holds 2.4 liters and you can see it at www.glad.com/food-storage/containers/large-food-storage-containers/. I usually get it at our local Costco or similar. You can freeze with it, microwave it, put it in hot water, etc. They come in quite handy and I have all kinds of various sizes to store other size batches of chocolate or colored white chocolate I use to decorate my pieces.
They have other plastic containers at Restaurant Depot that are quite nice as well if you have one near you. I use those to hold my sugar, my cocoa butter and my juiced nibs. I use smaller containers for all else.
The pans hold around 7 lbs (3 kilos) and have some room at the top for movement. In my typical run size, I fill 2 pans at a time then continue with another run. They store on baker's racks as 2 per level. I cover with foil and label them by batch date and code.