After few dives with this rig :
Camera - it's not D700 but yet, it's a good camera that can work very nice underwater. The video is a great bonus.
Housing - love it. Works great !
Macro - Works wonderful. I work with the 56201 105 DX Macro Port Base + the 56221 NX Compact Macro Port and it works like a dream for the 105 VR, 105 VR + 1.4 TC and the 60 2.8 macro.
Super macro - Use the 105 + 1.4 kenko TC + X5 or X10 wet diopter.
Fisheye - Using the Sigma 15 Fisheye with the 6' compact dome is possible, but using it with the 240 Dome is much better, even without any ext' ring. (I haven't tried an 20' or 40' ext ing yet).
Wide zoom - Using the 16-35 with 60 mm' ext' rings with the 240 Dome port got much better resolts then without any ext'. Yet, it's not good enogh for me ( Sea&sea recommends using this lens with 2 X 40 mm' ext' rings!!!) and I gave up on this lens for now.
My personal decision - Sigma 15 2.8 + 60 2.8 macro + 105 2.8 macro.
Love to hear your personal thoughts.