@mgaretz, I make lactose free ice cream all the time. I've never found lactose-free cream or half and half, but you can make your own by getting those liquid lactose enzyme drops. I generally add the drops a few days before I plan on making ice cream to the cream. My family and I are all lactose intolerant, and haven't had a problem with the ice cream I make so far.
For recipes that use skim milk powder, I've thought of adding the drops while the mixture is chilling in the fridge, but haven't tried this out.
