Do you feel the katana is worse than a little knife?
this mod gives new cooler animation and buff to the katana, making it useful when you run out of bullets or cut down those drug dealers faster.

install:
open your gta sa folder->models->gta3.img
use IMGTool to open the "gta3.img" extract the original "sword.ifp" and backup it,
then replace it with this "sword.ifp",
everything else just put it in your gta sa modloader.

note: in the folder Katana moves -> anim there is a cool ninja animation file, unzip it if you want to play around a bit (need new save), delete or compress that file to return to the original gameplay