Go and read link that Dumanthis posted, it contains pretty much all existing sources we have on them, which are inconclusive.
I went into AK to check out few stuff. At least from the sources we know that heavily armoured camel riders are not fantasy, I think we could have a sort of inbetween units. This means that most of camels will not have any armour, some with have partial light armour and all riders will be in cataphract gear.
Here is camel set I have assembled:
Btw, this armour looks sweet: