HI alaho!
To start with you need a good fluid tripod with friction, Sennheisser XLR shoot gun microphone which is in a range of 400 - 500 dollars depending where you get it. XLR to mini jack( similar to earphones ) and 20 meter XLR microphone cable.
As far as lighting goes you might want to check the LOWEL portable lighting kit. A friend of mine bought it somewhere in States, not sure where but they where amassing lighting set.
AS far as I remember you get: 1x 500w soft box ( umbrella lookalike ), 1x1000w and 2x 300w. All lights come with stands in a soft carry bag which you ca easily carry with you. I was interested to get one my self and the price I thing i was around thousand to 2thousand dollars.
One think you have to bar in mind in terms of shutter speed in D3s, I don't know if you can set it manually. It does say that you can set the ISO but as far as shutter speed I'm not sure. So make sure that that shutter speed is set manually other wise under florescent lights you get rolling bars.
Try and go to a local photo store and do some tests before you buy the camera other wise you end up with bars up and down the screen when you are filming.
Best regards
Valon