What to Buy???

[cw4u]

I have been doing photography for myself and my family for around two years, and now I want to start turning my hobby into a small business. I will mainly cover dances and sport teams for my local school district. I need help on equipment purchases, though.

I plan on buying the following equipment:
Nikon D-80
18-55mm Lens (Nikon)
1550 Watt Studio Lighting Kit
Bombay Grey Backdrop 10x10 w/Stand

Now, I remember assisting a teacher at a dance, and we just used construction worker lights, (2) his Nikon D-70, bench, props, and an old HP Photo Printer. As far as I can remember, nobody ever complained about the pictures.

Does the above equipment seem decent enough? Any other recommendations?

Thanks.