Thanks BCSticky, you're dead on in that thought. Window units can only have the front 4-6" of the unit in the grow space or you will be wasting the cooled air that the unit generates.
Since the whole thing will be in a space that is often at 90-100+ degrees, the back of that unit will have to have two separate ducts - one to bring cooler air from the outside to the unit and one to exhaust to the outside the significant heat the unit produces to make cold air.
What I guess I have to figure out is how to duct both of those and what other equipment (duct fans) I'll need to move enough ambient air to make the unit operate correctly.
Here's a link to illustrate what I'm talking about