Wow! Thanks Allen! I've not been to that part of FL before so it's all going to be new to me. The couple we're going with have spent a lot of vacations down there so they're pretty familiar with the area in a very narrow point of view (they are very much creatures of habit and won't stray from anything outside their comfort zone). Lots of good suggestions.
I was also considering are the Gulf Islands National Seashore and Fred Gannon Rocky Bayou State Park. I have read about Seaside so that could be a good trip, too.