I bought the same fan that CLC sells from amazon, before CLC added the fan to their website. We didn’t put in the headliner for our teardrop, but we might add it later on. Without the headliner, we didn’t need the plywood parts that CLC includes with their fan.
Any fan can fit onto the teardrop because you cut the opening for the fan out yourself. CLC doesn’t cut guidelines into the top hatch for you.