I did not know pressurized cream whippers existed until just seeing a reference to one, which led me to do a Google search. I own a manual cream whipper, which I rarely use, because it is exceedingly difficult to remove the cream from the canister.  So I just use the whip attachment on my mixer. I'm very interested in hearing  people's opinions on pressurized whippers, and whether they can be used for more than cream. 
The best storage depends on the particular confection:  Refrigerate (in a sealed container to not pick up orders or absorb water):   Ganache  Soft caramel    Cool dry storage, again in an air-tight container to minimize changes in moisture level:   Candied citrus peal Nuts - Dry storage Marzipan Raisins and other dry fruits  Fondant Hard caramel or toffee   Ovens without pilot lights probably qualify as cool dry storage, and will keep the pets out if you have any, but accidents happen.  I would use a cabinet or pantry if you have room. 