UHF yes, a must really as nearly all 4wd's will have one fitted, make sure it is a 5w jobbie
SAT phone, i say no, plenty of cars travel the main tracks along with you travelling with another car, although i did borrow a sat phone for the simpson desert
EPIRB good Q, i read they are changing the feq so i'm not sure how long it would be good for, i say no....your call
what else is needed, common sense, take your time and a camera to take plenty of pics for the trip report

