Re: boards for reef breaks???
Generally for more powerful and larger surf you go a bit longer, a bit narrower, and a bit thicker than your normal board. You also get a narrower tail, eg a pin or rounded pin, although a swallow is supposed to work here too, but I haven't tried it out on perfect reefs.
The increased length gives you more paddling speed and more rail, which means a better hold when riding down the line on hollow waves (or in the tube), and easier to carve at high speed. The narrower shape also makes turning easier when going fast.
Take your favourite board for every day use and build on that. Here in Australia there are stacks of second hand semi-guns in shops. Guys buy them for Indo trips then sell them when they get back. So if you can, get a second hand one as a back up because hollow reef breaks snap boards, and you don't want to be boardless on a surf trip.
Oh and don't forget to buy some reef boots! You don't want to miss out on surf whilst nursing cut feet. If you find it feels weird then just wear one on your back foot and keep the other in the pocket of your shorts.