When I brought my 20vt it came with one Red key, one blue key, a small round key and 3 code cards. 2 being thick plastic and one being like a credit card.

Are these cards anything to do with the alarm stuff? Would I be able to have fobs made up with these cards or does the alarm box need to come out and be sent away?

If you have no working fobs you'll have to get the alarm to someone who can fix it for you. There is a good address in the faq.