For big kings (close inshore) you cant go past live garfish and after that live frigates (and pike), and it really is amazing the places they hang out. I spent a lot of time fishing from the ovens and caught a lot of kings there, but the unlikley spots are best for the bigger ones such as south palm beach (shallow, look more like drummer spots). Greg Finney wrote an article many years ago titled 'Pike in Plain Places', I found this holds true. Live frigates at spots you wouldnt expect can really turn it on as can live garfish hooked behind the bum and drifted as far as you dare then brought back in across the surface (backwards). Unfortunately I only ever fished 15kg LBG so didnt land any of the truely big kings (20kg plus) but they are out there.
Basically use big baits and 100lb trace minimum. Not sure about big ones in the bays though, cant crack em.
Cheers
Ben