If you're going to target serious fish such as large sharks, skate sand sand sharks, you're going to have to get proper tackle. Graphite rods that can easily throw six to eight ounces at a bare minimum. Remember, it is not just the sinker weight to consider, there is usually a large head bait or dingle bait to accompany the sinker. Large reels with proper line capacity is required, such as the Stella 20k to 30k, the Daiwa Saltiga 20 and 25 k reels, and the Penn 8500 and 9500 as well as the Shimano Saragosa 20 and 25k range. Braid is non negotiable. If you can afford this tackle, try and save a little bit more so you can score a spare spool for each reel you have, ideally you should have two dedicated big fish outfits, along the lines set out below.
7 oz rod
20 k reel
Main spool 500 m x 40lb braid DNA as backing
Top shot 250 to 300 m 50lb DNA
9 m 120 to 150 lb braid leader
This will be your everyday outfit and will handle most fish up to and including 50 kilograms, so brown skates, blue rays, spotted gullies and hound sharks, diamond rays, smaller sand sharks and honeycomb rays.
Second spool - 500 m 40 lb braid DNA backing
450 m 30 lb DNA top shot
9 m 80 to 100 lb leader.
This will be for your edible species and usually where a longer cast is required.
8 oz rod
25k reel
Main spool 500m 50 lb DNA braid as backing
top shot 250 to 300 m 65 lb DNA braid
9 m 150 t0 180 lb braid leader.
This will be for the bigger class sand sharks, honeycombs, black fin, bronze whaler, grey and diamond rays, as well as the larger diamonds where you are required to pull very hard
second spool 500 m 65 lb DNA braid as backing
top shot 200 m of 80 lb DNA braid
9 m 180 to 250 lb braid
This is the rod you reach for when war is declared.
Big raggies, big bronze whalers, greys and Zambezis, black pylies, swim baits and sardine run shark fishing.
Hope this helps.