I also hate can'tpaymemymoney (cammpain), he's a bit of an ass, I'll help you help him sleep with the fishes.
Anyways, wholesalehyperperformance.com is a good company.
It is a bolt-on affair, IF you have head light support, if not, then you will have to take a trip to the hardware store and buy some metal so you could shape a L brackets (2x12 iirc)
MOST S13 Silvia fenders that come off front clips have dents, dings, and starches.. etc. So when you take them to the body shop to get painted, you also get the dents removed.
And you have to wire the head lights, which is not a big problem. Other then this, bolt-on.
Sometime you can score the conversion for a little less if you buy most of the parts separate, but sometimes this can backfire.
<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sly.gif" border="0" valign="absmiddle" alt=':sly:'>