While your at Leo's pick up a set of headliner bows from him, he will be able to point you in the right direction as far as what you'll need and supply with mostly anything also! Other than a couple of plastic clips on the center bow I can't remember anything else needed, unless you don't have the pieces along both rooflines with the teeth to grip the sides.
You'll probably be able to take a look at a car or two at Leo's with the headliner out to see what's missing
:welcome: to the FGMCC also, and good luck with your Monte!