That map was made by Splifington over at the BWGame boards. If it's just for personal use then I'm sure he wouldn't mind. But if you were planing on making it available, then it might be wise to ask him.
If you're just going to make your map look like Tropic then you shouldn't require Splif's OK. But if you wish to reach him leave him a PM on the BWGame boards.
If I remember correctly those gates are controlled by the game and do nothing in a skirmish map.