Cavalier

Cavalier has 1 very good exclusive and alright skill caps to back it up, making it a viable class to pick.
 * Cavalier can use the Griffin mount very easily - which is easier to drop and has more durability than Eagles. Because you don't need to offhand anything while flying, Cavalier Tomes are very high in demand - skip those by being Cavalier itself. There aren't many other notable items restricted to this class, but one huge one.
 * High Taming allows you to use relatively rare but powerful mounts, that are often too expensive to justify using. You could also just wear taming equipment, since you aren't going into combat often.
 * Skill Cap distribution is somewhat nice, saving exploration gear with a high cap. Don't pick this class as a martial user! Lower dark faith means you need an item/prayer to use the Shadow Wyvern. Some what lowered wealth and Magic which isn't too much.
 * You get a Healthy Brew and Taming Brew with the kit, which is good for any situation when you can replenish them easily.
 * Better invest into Spears and NOT martial, as well as taking advantage of 23 exploration.

Skill Caps

 * Blades: 20
 * Spears: 23
 * Martial: 16
 * Ranged: 20
 * Magic: 19
 * Dark Faith: 16
 * Raiding: 19
 * Leadership: 21
 * Labour: 20
 * Exploration: 23
 * Defence: 20
 * Taming: 27
 * Light Faith: 18
 * Wealth: 18