For the really big sharks most like a specialised set up. I'm not into that so can't help you with a specialist outfit. My heaviest beach outfit is a penn spin fisher 950 loaded with 50lb braid & matched to a 4.2m 8-15kg Rovex Aureus rod. IVe caught heaps of big fish on this outfit including sharks up to 2.1m long.

My "all round" set up is a 9ft 5-10kg Starlo Stix rod matched with a 5000 Stradic loaded with 15lb braid. This outfit is fantastic for throwing lures or mulies at salmon & tailor in the ocean but is also sensitive enough to double up on whiting & other small species in the ocean.

I would suggest a third outfit as well for chasing, bream, flathead & tailor in the rivers. This outfit would be a 6-7ft 2-4kg rod matched to a 1000 or 2500 size spinning reel & loaded with 6lb braid. This is ideal for flicking lures or baits in the river when the heavier fishing just seem like too much hard work.

 your best bet would be. 

when you land in oz go to your nearest specialised tackle store (not the chain stores) and they should be able to fit you out with the right gear for what you need. not all rods suit all people as the butt length is different as is the weight of the set up you get. if you have short arms you dont want to be using a rod with a long butt and visa versa