Sally Beauty Supply's Kolestral Conditioner, buy it by the gallon, around $26 and it will put an unreal shine on his coat. I use my hands to smear it all over like mayonaise and rinse it out with warm water. It'll come out with cold but takes longer.
Show Sheen by the gallon.
Ultra Products, Clear Hoof Polish and Meltonian waxy shoe polish in whatever color your horses hooves are. Ultra Hoof Polish Enhancer Spray and Ultra Hoof Polish Remover. I put the wax on the hoof first, then the polish and let it dry for about 30 mins, then spray with the enhancer when the polish is dry to the touch.
Healthy Hair Care Spray in conditioner, concentrate. I use it every day.
Pepi coat conditioner for just before you go in the ring.
Ultra Sparkle Light Coat Oil if you're showing halter.
Baby oil gel for 'face make-up' if your breed does that. I use it around the eyes, on the muzzle so it looks shiney black and not grey and around the anus to show the judges how meticulously groomed the horse is. Yes, only Arabians are THAT picky.
A full set of clean combs & brushes for show day only. I NEVER use them any other time and wash them out after every show and get them set up again right after they're washed.
I keep a set of all of these products packed in my trailer, ready to go and woe the fool who touches them when we're not at a show. I like to know all I need to do is walk my horse into the trailer and drive off and we're ready.