i currently dont have one at all. just an open space in the headliner.

i have been searching the interwebs and i am more confused than before i started looking.

anybody found any good aftermarket universal type dome lamps and lights to fit in there (or even requiring modification?)

would like to tackle this before i go and do the actual headliner so i know what im getting myself into.

Id just drop one in from a scrapped XJ imho. Personally Id like to have one like what's in my hatch up front.....but you know the saying if it ain't broke don't fix it lol.
That's the route I would take.