I have owned and used a Nikonos V with all available lenses, a Subal housed Nikon F4, and a Nikonos RS with all commercially available lenses, the German 18mm lens, as well as a tele-extender made by John Ratterree and the one made in Germany. Both of these tele-extenders are similar but the German made one is optically aligned with and optimized for the 50 mm macro lens. The tele-extender essentially gives me all of the advantages of a housed 105 mm macro with the exception that the autofocus on the Nikonos RS becomes painfully slow as lens length increases when one approaches a magnification ratio of 2:1. As a consequence of this slowness I compose with power manual focus and move the camera for fine focus. I prefer the Nikonos RS system to either of the other two systems primarily because of the water contact optics (compared to a housed system) and through the viewfinder composition (compared to a Nikonos V).
For strobes, despite the cost, I prefer my recently purchased Subtronic strobes over any other strobe I have used or even seen. These are unquestionably the best engineered strobes I have ever seen. I use the Subtronic strobes for wide angle (although they could also be used for macro) and Nikon SB105 strobes for macro. To charge the nimh batteries of the SB105, I use intelligent Anson chargers purchased from Woody Mayhew in Texas. I use both TLC and Ultralite arm systems on a TLC flip tray. Neither of these arm systems is perfect but they are adequate given no better alternative.
I use Fuji Velvia for wide angle shots and for macro shots shot at ASA 50.