Boca Grande is going to be your best bet and that time of year is the height of Tarpon fishing in the area. You'll see thousands of them boiling in the Boca Grande pass. We have fished a few times with
www.captwaylon.net and have had multiple Tarpon each time. The weeks surrounding either side of Memorial Day are usually the best.
A lot of the traditional Boca Grande tarpon fishing is done around hill tides which occur at specific hours of the day and night. Let your Captain tell you what time you want to fish and don't try to force him into a specific time if you want a better shot at them.
It's an amazing fishery and will be an awesome experience for you and your family.
Good luck.