Nanner,
You can make a simple damage texture by just copying the texture, darkening it a lot, and adding the "d" to the end of the filename. There is a catch though. I have not had much luck with post-market damage textures. One thing is the mesh. If it's not completely seamless, then the damage will not show up right, or not at all. Another thing is the damage points on the model. If they are not situated on the model where damage will show (ie: if they are in the center of the mesh or not there at all) then your damage will not show up. Also, you may have to run the model through the Taldren recacher program to make them work. That last part im not sure about, since I've always done it anyway.
About the break model, if you email me the model I'll do a simple break model for you, like the models of TNZ.
Also, I'll take a look at the damage points on the model, and rearrange them if needed.
It's surprising to me how many veteran SFC modelers here do their damage points incorrectly.