Since we're talking about your 4th goalie it probably won't make too much difference but I think I would hold onto Raanta for now. He's barely had a chance to get going this season so we don't really know what he's going to offer. Luongo I think the odds are pretty low he tops 45 games, between Reimer playing and his injury history. You already have 3 good starters so I would want to just hold onto Raanta who has a chance to really hold onto the crease, whereas Luongo will be good some weeks and absent others.