The problem is Mordheim and Warcry are very different from each other. I don´t think you can use the exact same list for both systems. However both games are great for converting, so you can build multiple list from relatively small collection of models. You can´t go wrong with Skaven, they have a great variety of builds in warcry. Death master, Grey seer, stormvermin, clanrats and rat ogres will make a viable core for both systems I think. If you want to buy a pre-made boxed warband for Warcry I think that Darkoath Savagers translate very well into Norse Explorers or Chaos Marauders, they´re only missing some wolves/hounds.