Air handlers and furnaces aren't often used in the same home in Cocoa. If you use a furnace, you likely won’t need to consider an air handler.
Air handlers are typically paired with heat pumps and control airflow throughout your residence. Some units also offer backup heating and cooling components to help the heat pump.
A furnace runs in a different manner by sending heated air into your vents, which circulate it around your house. As furnaces have combustion chambers to produce heat, they don't have some of the components you'll find in a standard air handler.