You will get lots of opinions on this subject. I catch fish on the reef so here's mine ....
- 8/0 circle hooks work well, particularly if you like leaving the rod holstered while you sit in the shade and are using braid.
- 8/0 suicide style hooks also work (my favourite at the moment)
- a couple of gang hooks with little or no sinker out the back for pelagics also works well - snell them together as spaniards are rather curious so great presentation is essential to maximise hook up rates
- use green fluro tube on paternoster rigs - you will be amazed at how well small lengths of tube work and it adds a bit of anti-abrasion to the leader
- in the end, bait presentation (eg 1/2 pillie stuffed into a full squid) on seriously sharp hooks is the key as reef fish usually smash baits
But my decky will tell you 5/0 is all you need and we usually share the honours!