Actually, I don't really. I tend to go through ribbon cables, since I weed out the ones I don't like. Ribbon should be cheap. Don't get anything but the 80-conductor if you are going to buy new cables. They have less crosstalk to handle the higher speeds of new drives.
dash, go with ribbon rather than round. You can route them much better , flex them at right angles and such so that they are flush with the edges of the case. Well-routed ribbons look nicer (IMO) than round cables, and they actually do breathe easier in the case.
Plus, I said so.