Earnie, what an interesting thead. You have a friend who is going racing but needs an outfit or is he just modeling for the crowd??
A license for starters if he is lacking all of the above said equipment would be the best start.
A HANS device would be 2nd along with a a date check of the harnesses. Extra tires, bottled water, like 5-6 liters worth for a weekend, granola, apples, bananas (you might have him covered there), I assume you are discussing Hawaii...A Cool Shirt setup. Floor jack, tools , spare parts, trailer, truck to tow it with.
Oh and a scooter to run around the pits with.