I would love to see the plans. If it is a true full set of construction documents, you should not need an architectural stamp for residential in Duval County. Almost any residential engineer will be able to specify hold-downs, nail patterns, lumber size, etc..... The plans must be engineered for Florida wind codes and have the engineers stamp affixed (I am guessing under $1000.00). You will also need an energy letter to turn in with your plans for permitting. The energy letter will take into account the location of the building, size and number of windows and helps to determine HVAC size and hot water heater size (Call Energy Design Systems, they are in Switzerland, South Mandarin). It sounds like you have quite a bit of construction experience. Looks like a fun project. The lot looks great (Very Florida). Can’t wait to see the progress.
If you need some professional advice, don’t hesitate to give me a call, you know where I am.