new to.. well, everything!

I'm soon getting out of school for videography, and have been trying to figure out my niche. I've always wanted to do underwater shoots, and will soon be in the process of getting my c-card. I understand that doing video underwater is completely different from land, so it should be a fun challenge . I was wondering if someone could recommend a good set-up? I was looking at some of the Ocean Brite's covers, because they ahve some for pd-150s, and 170's (which i'm very accustomed to). But i understand that housings made of aluminum are better? And if anyone has recommendations on a camera that does exceptionally well in water i'm open to all sugesstions. Its just that its nearly time to get a camera for land shoots, and it'd be nice to get one that does well in water as well. I do want to start off with a professional camera, and because i don't want to have to replace it anytime soon, suggestions for good underwater housings are needed as well.