Since you seem to be concerned about weight and the I suspect you might be thinking about checking it for flights rather than carrying it on. Well I have some reasonably good news
I recently help my girlfriend take a hard sided carryon and modify it to take an ikelite dslr housing, body, 100mm macro lens & ports, ds125, chargers, 8inch dome and 10-17, arms, tray,
and sync cords. If you go othis route it's strongly suggested that you take a photo of the setup, print it on 8.5/11 paper, laminate it and put it in the carryon. This will help you if you forget
exactly the way to put everything back with the foam, etc - plus every once in a while you get shafted by the airlines and you get stuck checking your carryon. If TSA opens it the picture/packing
instructions are your best hope of keeping them from screwing everything up.
Have fun with your system - I just got a d7000 in a used nauticam housing and can't wait to try it out in a few weeks!