New to UW photography ?'s

I am interested in shooting some UW stuff but I dont know where to start. I figured I would pick up a book first but I thought maybe someone here could answer a few quick questions to get me started.

I see all these camera packages and deal online but what does a person really need. I would like to shoot both still photo and video so can I get a single camera that will do both well for less than those $2000 or $3000 packages.

Do I need strobes of ordinary HID lights.

What are the large housings for.

I am not looking for production quality movies just some good home video. My interest came up after signing up for a cave diving class so I am very new to the idea.

Thanks

The first choice you need to make is do you want to shoot video which can take an occasional still, or mostly still which can take short video? You do sacrifice quality of the secondary type depending on which is your priority. To my knowledge, there aren't any systems which do both equally well at a high level.

From that you can move on to lighting and such.

There's a sticky at the top of this board by Alcina with answers to a lot of the basic questions.