Gidday Renos,
Where I am in Australia, to go on the armoured vans you need the Security Guards License, Security Guards Weapons License (Class H - pistol), and truck license minimum category MR (Medium Rigid). They travel armed here, with glock pistols.
There will be differences in your area, possibly on the weapons license/armed.
Probably would pay to get in touch with the money carriers and ask them what their minimum requirements are in terms of licensing, and what they are looking for in terms of experience.
As for who they are over there, I couldn't tell you, but maybe if you are seriously interested someone on the forum can point you in the right direction.
I'm pretty sure over here ex-military, ex-police is an advantage, but not essential.
They run plain clothes CIT here as well, with truck license not needed, but weapons license essential.
Have looked at it here myself, I am planning on giving it a run next year. Money is average, however it's another area of experience for the resume.