The basic difference between salt water and fresh water fishing is the maintainance required to keep gear healthy. Salt and corrosion (sp) are one of your biggest enemies.
I DO use graphite seats for my salt water rods, which is most of them now. We even double wrapped a 3wt (and a couple others) for SW use. I don't think constant washing can be over-emphasized with salt water use.
Sand is another concideration, especially when thinking about reels.
.....lee s.