Unless there is a load of fluff I've not seen, Ferrus has metal arms from drowning a wyrm of some sorts in lava, I believe it's described as his hands/arms coated in living metal. I don't think I've seen anything to suggest that he had any bionics and the chapters fixation with bionics started post heresy.
I was really disappointed with their portrayal, I take some solace in the fact that it was the first time they had a primarch refuse the offer to join chaos, especially since fulgrim and ferrus had supposedly been amongst the closest of any of the primarchs. I really hope we get to see more Iron Hands since currently theres just fulgrim and an out of print novel.