I’m from SWFL. About the only game in the summer in the surf is snook. Snook move out of the back country into the surf during the summer. I never fished Siesta key beach but I used to fly fish for snook on venice beach in the summer. Your outfit will work for beach snook but add a 2 foot leader of mono or floro to the end of your braid. 7 foot rods are a standard. White colored jigging type lures are popular. White Buck-tail jigs , white or slam shady colored plastic 2.5-3 inch paddletails are popular. Get out in the early morning or later in the evening. Water is hot. I don't fish in July or August but if I was to I would focus on beach snook if I was shore bound.
If you fly fish a 6-8 weight 9 foot rod is standard. Again white flys in batfish patterns are good. Deceiver's , clousers and most popular is the white Shminnow. I find when traveling fly fishing gear is more convenient. If your driving I guess it doesn't matter.
Wash off your outfit good after every time fishing. If it isn't saltwater type equipment you might find you need to replace the bail roller bearings when you get home. Saltwater is brutal on fishing gear. Be sure to take off the reel and wash the reel seat on your rod as well as the rod guides and where they meet your rod. You probably know all this but just in case you don't there it is.
Add Mirrolures and Yo Zuris. Don't be afraid to use some scent on your lures. You'll get more hits.
If you want to use live bait. You can go with some pin fish, grunts and finger mullet if you can get them. Snook will hit a dead mullet fished on the bottom. Set that line out in a pvc beach setup and fish the other lines.
Good luck!