If you pause the game you don't know if what you do makes them happy, so it's hard to build thier exhibit that way. The easiest thing would be to check out Wisco's, you'll get the guide for very high suitability there.
Or you can place one snow leopard in the exhibit, make the suitability as high as possible, then sell that snow leopard and put a new pair in-they will start off in a highly suitable exhibit and you won't have to go through the trouble of having it go down while you are building the exhibit.