So you are looking for a studio style strobe?
Studio strobes have a trigger socket, it's usually a standard 1/8 mini-phone type plug. So if you are using a cord or wireless receiver, you would need a cord that plugs into the socket on the light. The 'PC' connection is the universal type connection for the camera end of the cord. I don't know why, it's a terrible connection.
So if you buy a studio strobe, it will likely come with a PC to 1/8 cord.
Now, the problem is that I don't think your particular camera has a PC port (it's usually only the higher end cameras). So you would need another solution. One would be a
hot-shoe to PC adapter. It's a 'box' that slides onto your hotshoe and has a PC port to attach the cord to. A better solution, IMO, would be an
adapter with a standard 1/8 socket, then you could use a standard 1/8 to 1/8 cord.
Even better, would be a wireless trigger. That way you don't have to worry about cords. These have been discussed, every other day, on the forum for a long time, so you could search out a lot of good info.
HERE is a cheap kit.
Lastly, most studio strobes have a built-in optical slave cell. That means that when they detect another flash going off...they will fire as well. So really, you could use your SB-900 to trigger the strobe....but this means that you have to have the SB-900 on-camera and have it firing, which may add light to your scene, that you don't want.
