I haven't ever heard of using an aloe plant, so can't speak to that. Sanseveria is a really good plant to put in a gecko tank. It's safe, and sturdy enough for your gecko to climb on. If you like the look of the aloe plant, you can sometimes find a fake one at Hobby Lobby or similar stores. Maybe someone else can tell you whether the real thing is safe for your gecko.
Do you have a vivarium? I don't, and use fake plants in mine. Thrift stores are a great place to find greenery.