Fender,
I was a fresh water fly fisherman for 40 years, then 10 years ago, I booked a trip with a guide in south Louisiana and caught my first redfish. The rest is history, as I now own a kayak, a bay boat, and about 4 rods that I use, depending on species. I would recommend an 8 wt rod with a wf floating line. With the heavier flies like spoons and clousers, and the more wind resistant flies you are going to need the extra punch. Also, on the coast, the wind is ALWAYS blowing, so you need the extra backbone in your rod to handle that. In the gulf and marsh, we catch reds, specks, lady fish, flounder, spanish mackerel, and jack crevalle. I have not caught a triple tail yet, but will keep trying. As for flies, clousers, spoons, crab and shrimp, and any bait-fish profile in the right part of the water column should cover most of your inshore fishing. Kayak fishing is a hoot. I would look at the Native Ultimate 14 for a kayak that is easy to paddle and you can stand up in it. Good luck and tight lines.
Frank