There's a a model3 cheat database at https://github.com/john-peterson/bin-patch
You're welcome to request cheats or post cheats you've created!
To make artmoney find the right address so that the cheats work you need the .emul entry for model3 from here viewtopic.php?p=1029#p1029. Add that to artmoney's .emul file.
The thread for the model2 cheats are here http://www.speksnk.org/foro/viewtopic.p ... 29#p570629.