Hey Chris,
Jax Beach is a great area. It's a little tough to find good deals these days though. But there are still some out there. If you prefer to be hands-off with full-service management, then I'd plan on paying around 20% commission as that's pretty common. To Chris' point, you can find lower options if you handle some of the management responsibilities. In my opinion, your occupancy rate and min night stay seem in the ballpark for planning purposes at this stage. Your nightly rate will be influenced by proximity to the beach, interior design and amenities (ex game options, fire pit, pool, etc). I didn't see a budget line item for furnishings, interior design, and amenities. Depending on your goals, budget somewhere around $3k-$5k per room. Hop on Airbnb and scan nearby properties of similar size to get a feel for what they offer at the price points charged. Some tools that might help at this stage include AirDNA, Rabbu, Airbitcs and or STR Insights. Hope this helps.