I just put a light on my 230f a few months ago for about 40 bucks (US). I got an old light of an XR400 from ebay and an on-off-on switch (or high-off-low). I wired it to the ignition so it only comes on when the key is in the on position and used an inline fuse.
I had to use the rubber from a bike inertube wrapped around the forks to make the ruber mounts fit the smaller fork. I have pictures on my website from when I first hooked it up. I have since made a little bracket out of aluminum so the light is in better position.
Hope this helps some,