sounds cool
I'm in FL too (561 represent), i went tothe beach last week and caught a bunch of golden pilot jack like 1-3 inches long. and those can be pricey, i thinkthey sell for 60 bucks on liveaquaria for similar size.
also, have you thought of a juvenile look down? just throwing that out their.
and when he gets older you can sell him and make a boat load of cash lol.
now, i have heard that when the pneumatocyst pop they release chemicals that will kill fish. I think its that the algae has a secondary metabolite that deters predation. i'm not sure if its true or not, have you looked into that?
also are you going to sterilize the algae or go au natural? they often have byrozoan colonies and hydroids, though i have occasionaly scene anemones that resemble aptasia.
and, what kind of sargassum shrimp are you getting? I have the target one, and he is B.A. he would taunt my sargassum frog fish, he even taunts and attacks me when i stick my hand in the tank lol. anyway the reason i bring this up is some of them glow green under the right lighting.
have fun and be sure to post picks.