Alright, so I've been taught about the statting for pets when it comes to missions and battles etc, however I am unsure of the armour I should be using.
So will someone please give me examples of armour for the tank pet, dps pets, and then what armour is best for each pet that would be on missions.
My pets that go on missions arent very high in level at the moment, but I will be hopefully leveling them up soon or buying new pets.
Any help will be highly appreciated!

Basically, you need to look at the stats on the equipment and ensure that:
(a) the two highest stats (strength, dexterity, intelligence, agility) on the equipment are the two stats you're trying to make the focus on a battle pet; or
(b) one of the two highest stats (strength, dexterity, intelligence, agility) on the equipment is the stat you're trying to focus on for your mission pet.

I would expect it to be something like this:
Tank - Assassin
Physical Attacker - Myrmidon
Magical Attacker - Evoker
Strength - Myrmidon / Crusader / Assassin
Dexterity - Myrmidon / Warden / Evoker
Intelligence - Evoker / Crusader / Illusionist
Agility - Warden / Illusionist / Assassin
Health - type doesn't matter as they all have about the same health

Awesome!! Thank you so much!