Spraying with rattlecans-amount needed?

If your doing it right I'd hazard a guess at around three 400ml cans of a paint like montana. Although I probably wouldnt use five coats tbh.
Painting cranks is fine although they will get scratched up so expect to have to re-spray them.

Not sure if your looking at a multi colour job but armourtex is alot cheaper than £180 utfs.

How many coats is enough then? =)

I live in Norway, there's no Armourex here. I've read about them here on the forums, and the prices aren't half bad, but I'd have to fly to London.