For anyone that wanted to do earpad swaps, below I will provide a link to a place that makes good rings. In addition I have the angled velour hm5 pads on em and I love it. It does bottom out the headband sooner due to the extra padding so I would also recommend the regular velour pads for the hm5.
http://www.modhouseaudio.com/akg-kxxx-adapter/
http://www.modhouseaudio.com/akg-kxxx-adapter/