Blazer. Mohawk or Classfive built with a removable motor mount. The Blazer is a great canoe for most of Florida and easily to find used. The biggest problem I see with the Blazer for you is the load it can carry for camping. As a scout leader you probably will be carrying quite the load on the camping trips. You might want to get something a little deeper like an Mad River Explorer. Carry a little more weight but will catch more of our afternoon sea breezes with its higher sides. Stay at around 16 foot in leangth to make it easier on some of our spring runs and creeks. Much shorter really hurts your speed. Not that a blazer or Explorer has much speed to begin with. Classfive is making the Blazer in Kevlar, Not the lightest boat around but still easier to carry than most canoes found in Florida.
If you really want to get a good canoe and can afford them Northstar Canoes are being sold in St, Petersburg Florida by Sweetwater Kayaks. Look at the Northwind 16 or the Seliga would be perfect for you. Maybe you could go with a 17 foot Northwind. My pick in Northstar canoes is a Polaris. But bringing new to canoe kids in a scout troop along and wanting a motor makes this a poor choice.
Canoe country outfitters also in St.Petersburg has a large stock of Wenonah canoes. Loved Wenonah when I was younger now they just miss a certain something the a DY designed Bell(now Northstar) brings.
Please stay away from the Colman canoes. There plastic likes to warp and oil can especially in the Florida sun. Indian River canoes can be found all around but they should be considered below a Blazer, New square back Indian River canoes can easily be found.
Do not forget to budget for good paddles, In a lot of places in Florida the sugar island style (sort and wide) has an advantage over the animal tail (long and narrow) style paddle in shallow spring runs. I prefer Bending Branches and Grey Owl brands but their are many other good brands. Try to stay away from the aluminum and plastic paddles. They just do not grab the water good. Although they can make a great spare.