I dont think there is a light in the middle from factory, I believe it is just a little push in trim cover to cover up the screw, I think the picture was the alarm light somebody installed aftermarket...
In regard to the cover piece that covers the screw on the top of the seatbelt, I was just going to use any of the covers that are on most cars. They are all pretty much the same size. Tonight im going to see if the Durango covers will fit.