You may, if you wish, carry a whip. The horse must have a halter and a throat latch. Your lead rope can be one of your liking. As you can see they are very fine and delicate looking. The small chain throat latch is required in order to show.
Arabian halters vary from plain to fancy and inexpensive to very expensive.
A leather lead, or one that matches the halter, with a chain at the end is what is usually used. There are no real requirements on attire for Halter class. Generally, you will see men in dark pants, jodphur boots, shirt, vest, tie, and occasionally a suit type jacket. Hats are also worn by some competitors. The ladies quite often get a bit fancier than the men donning fancy jackets and scarfs.