Welcome to the forum Kyle.
As ZoddyZod has suggested, an alligator gar is far too large for any reasonable aquarium, although his numbers are a bit extreme. Fortunately the ones you have only grow to about 2 or 3 feet, which is way to big for your present tank although it can be accommodated in a home aquarium. Any gourami that we would typically see will not go over a foot long but the kissers are definitely among the larger ones that sometimes are seen as big as 8 inches in an aquarium. If you keep an eye on things you should have plenty of time to accommodate any of your present fish or at least find them a new home before they become too big.