I won't disagree that a C310 isn't a good choice, I have 2000hrs in them flying freight, and absolutely love the plane. It would be a good plane for the mission. Problem is you have "Full De-ice" and "Known Ice" varients. The difference is the FIKI models have a heated windshield(which sucks 95% of the time when you are flying every day), vs the Alcohol windshield(which I favor except for when icing is all the way down an approach). There aren't very many FIKI C310's out there, so the "Full De-ice" is more popular. At that point, you really have to weigh the additional costs etc... of finding a good FIKI vs the other.