For general reef fishing in an overhead combo, a good starting combo would be a Shimano TLD 15 on a 15 kg or 15 -24 kg rod , using 50 lb braid with 60-80 mono or flurocarbon leader, using 7/0 -8/0 hooks. The TLD 15 is great value for money, and you dont need a bigger one as it will hold stacks of line. Dont be tempted, as you want to keep your rig as light as possible. I often see blokes with way over the top size reels which require tons of line to fill the spool, and its just a waste.
The key also with rigging with braid is to consider loading most of the spool up with mono line which is cheap and then loading about 200 metres of braid on the top. Thats if you are wanting to save cash. The amount of braid required to fill a generic reef reel is quite expensive. If going on such a trip, which will be great fun, always take plenty of spare line , hooks, sinkers, especially reef fishing, to cover for bust offs etc. Generally when fishing coral as well its best to fish straight up and down, vertical, as casting out aroung reef will garuntee or greatly maximise snags and a lot of lost gear. Coral trout in particular will drag you under coral in an instant so you need direct contact with the bottom, and no slack, did you hear me? no slack. You will have a ball!!
Cheers