I would also go with the Captain on this one. I have dove with an Ikelite housing for a point and shoot and a Nauticam with a Nikon D7000. The Ikelite is a nice functional housing. The housing price is about half that of the Nauticam. But once you add ports, strobes, focus lights and so on, the price difference is not that much. The Nauticam is quite a bit superior to the Ikelite in precision of controls, and ergonomics. I was thinking of getting the Ikelite but my wife put in a big push for the Nauticam and she was right.
For lenses, the Captain is pretty much on target there too.
The Nikon 60 mm macro lens is good for medium fish and close ups. The focus distance is a bit too close to get true macro shots. You just can not get close enough to your subject to pull it off (usually). I would strongly recommend getting a focus light like the Sola.
The Nikon 105 macro lens is better suited for true macro because it allows some "stand off" distance. It is also probably reasonably good on small fish.
The Tokina 10-17 fisheye is a great underwater landscape lens and it is good for very large subjects who will let you get close. It has a really close focus which is great. The close focus allows you to use a very small dome which makes for a much more compact unit underwater. The lens also makes for nice shots on the boat coming back. The fisheye is forgiving of focus and the warped field of view makes for nice funky photos of people who have just been underwater for about an hour. I had not thought it would work that well in this application.
The last lens I would suggest is the Sigma 17-70 "macro" lens. It really is not a macro lens. It does allow close ups. But you really can not do small subjects justice. You can do landscapes in a pinch but not as well as the 10-17. The lens does work well on fish though. You have enough reach to get nice shots of grouper, angels and so on. Also the zoom allows you to zoom out on larger subjects. The lens does require at least a 6" dome or better yet a honking huge 8" dome to work well.
I use a mix of Ikelite 160 and 125 strobes. They work well for me. They are a bit heavy but they recharge great.
Something to think about. You will probably want to cram all of this into a carry on piece of luggage. The weight adds up. It is a bit of a haul. It can be done but it is a bit of a chore. Also, handling the thing on a boat is a bit cumbersome also. This isn't your point and shoot set up. Don't get me wrong, I really like it. But I don't mind the weight.
Also, given the fact that you are laying out this much $$$$$$, you might consider getting either the D800 or D600. The price of the system will not be that much different. You can use the 60 mm, the 105, and I have heard even the Tokina lens with the full frame versions. I have not considered what one could use for a mid range zoom with a full frame.