Storing whiskey, even your most prized bottles, is a much easier task than wine, as you don’t need to have a fancy cooling system, cellar, or wine fridge. What you do need is a location that is relatively cool and protected from sunlight exposure. Often the far corner of a cool room will be the perfect location for a bar cabinet, cart, or shelf. The basement, closet under the stairs, or garage are all the wrong locations to store your bottles, as their extreme temperatures and humidity, and dankness can wreak havoc on the liquid inside.
Unlike wine, you also want to avoid storing the bottles on their sides, which is why a shelf, cabinet, or cart are ideal. Storing whiskey on its side can cause the higher alcohol to eat away at the cork, which can cause the bottle to start to leak and cause the cork to impart not-so-pleasant flavors in the liquid.
If you plan to collect these bottles for potential resale, then perhaps consider investing in a cabinet with a lock, and ensure when you store your bottles, that you leave plenty of space between each so that the labels and glass stay nice and pristine. Buyers care about these sorts of things.
Finally, once you open one of your expensive bottles, make sure to return to it somewhat regularly, as whiskey will oxidize over time. The last thing you want is to share a dram of a special liquid with a guest, only to find it isn’t as delightful as it was when you first opened the bottle many years ago.