In my opinion, this depends on what the teams before us decide. In general I agree that leader is more important than Civ in this situation. Mostly because goodness of leader depends mostly on settings that we'll know before making our pick. On the other hand goodnes Civ depends much on map and I guess we don't get any more info on that before getting our pick.Seems to be a consensus thus far that a leader is more important at present. I support the above post with Darius and Pacal swapped.
However, if all teams before us pick Civ at the first go and we pick leader, we'll get first pick on leader but the last pick on Civ. IMO, it is better to be fifth on both rather than be first and last even if we appreciate leader more than the civ.