The power port "retainer" as parts4chevys.com seems to call it, is under $5 list price at the dealer. Recommend you just go there so you can confirm it's the right part when you order it. As a trim piece, it's not going to be seen in the aftermarket. Although there are MANY receptacle covers available in the parts stores. Assuming you even need it covered. Why not just whittle off the stubs of the hinge plastic and put the cap back in the hole?
Many folks have put LEDs in the HVAC circuit board, or you can solder in a replacement Radio Shack lamp. Have you disassembled modules like this and can you solder?