“How Do I Choose?”
If BUDGET is a main consideration, you may lean toward Drop Flue. It has slightly lower cost; in part because it employs only one Float Box, while Raised Flue requires two Float Boxes. Having a single Float Box makes the system slightly more straight forward to operate as well.
Next, what SIZE evaporator are you envisioning? If larger than a 2′ x 6′, we typically encourage a Raised Flue Pan Set. This is because the head pressure from the Raised Flue Pan will allow sap to recover more quickly in the Front Pan whenever you draw off syrup.