Small 355 with a great cam and CMI headers in a 19 footer I have some 20 year old fresh heads with new stainless 2.02 that are slightly worked in the ports. Was thinking some Vortecs but by the time you mill the spring seats for A bigger cam it starts to add up.

Any other suggestions?

If you go to Summit Racing's or Jeg's websites there are tons of choices for SBC's. You should be able to find a set to fit your particular displacement, cam, intake and exhaust combination. Darts Iron Eagle series heads are hard to beat for the price and require very little, if any modification. I ran Dart Iron Eagles on a pair of 427 strokers I ran in my old Magnum with very good results.

Why not use the 2.02s you have. Just use Salt Away or equal when flushing the motor after each use.
I use my 22' exclusively in salt water; it has iron heads on it that are 15+ years old now, no issues (yes it has been apart recently, all looked good not much corrosion, put it back together no changes).

EngineQuest heads !
By far best bang for the buck and cast iron.