Chowder,
You will need a Penn 345 for 600' of copper, 300 yds of 50 lb. backing, and your leader. An offshore inline will not work on 600'. You can get away with 300' of copper with a spoon behind an offshore but it does not run that great. You also have to modify the release by adding a rubberband. You are better off running it down the chute or off of big boards.