What do you use your Bronco for? Daily driver or mostly an offroader?
Poly bushings will act almost like an anti-sway bar and noticeably limit articulation. If its mainly a street rig I'd say poly. If you value articulation highly when offroad put OEM rubbers back in the C-bushings and radius arm frame donuts.
Use poly in the trackbar ends regardless. It will tighten up your steering and help eliminate/prevent death wobble.