3wt for the first and second troughs throwing out a shrimp or crap imitation was always fun for me, Flounder, Whitefish and Pompano this time of year on the Atlantic. If Jacks, Tarpon and Redfish are possible target then an 8wt with a Cloz or a Shrimp imitation work.
If you are going with a spinner or baitcaster you will want to rig up a "fish finder rig" and try and hit the 3rd trough if one is there or find the channels by watching and reading the water.
As for Marco Island I only have two words ( Back Country ) God on the 8th day said let there be the back country for anglers to appreciate me and spend time with me, let it be plentiful in bounty and bring peace to all's hearts. It is one of the few things I miss about Florida