I can't speak for lighting, but I've got both a PA/Siren horn plus two air horn pumps all mounted back by the steering wheel area of the firewall. There is some space there, on the firewall for such things. I have the siren facing down and an L mount tapped into the firewall to mount both compressors. I don't have time right now to take a picture, but there is room in that area of the 4.7 if you work creatively.
I've seen some drill holes through the luggage rails while there off then mount a al crossbar at the front leading edge of the rails on top. From there they've hung or mounted all sorts of lights,etc. I personally have a RIGID-type offroad light on mine.
WJ 4.7L*245/75R16*Mopar Front/Fuel Skids*KOR T/C Skids*JCR Sliders*Flowmaster 50*Airraid MIT*OME HD*Bilstein 5100s*JKS Trackbar*ARB Bumper*SB XRC 10*Zone links*Almost as much electronics as Batman..