Refugium Recommendations

[Jaws]

I have a 100G Refugium that I'll be setting up in the next couple weeks and I'm looking for some recommendations on what sort of things are going to be the most beneficial to grow. For starters, the tank is Divided in the center so there will be two totally separate areas but they will be equally fed with about 300GPH. I know chaeto Is probably a must but what other things including substrate would you use if you could do it all over again? Thanks