Dan, I'm getting ready to replace mine, as soon as I get through with some transom work I'm doing. I'm considering using 1/2" starboard. I don't where you are in fl. but I belive Jacksonville is where much of it is produced, and it can be found all around the state.
I found a place in Ft Pierce that will sell pieces of it by the pound. They also had sheets that were 54"x96" I believe for $225. You could do both sides plus a bunch of fishcleaning pieces with one sheet. Mike