Keep in mind also what headliners are interchangeable; I put a headliner from a Spirit Kammback into my SX/4 Eagle. The Spirit was an inexpensive model and didn't have fancy trim, just vinyl glued on a piece of cardboard.
A headliner from a Gremlin will work in a Kammback or SX/4. These are just color printed on a piece of cardboard. If you get lucky (like I did) you don't have to paint or recover anything. The parts are original, and you can save some money.