If you'd like, slender, I could help ya with the mod. :> I can get you more of the source models. The only ones available though are:
Spoiler
For things like the shadow animatronics and Golden Freddy, all there really is to do is replace the textures. I can also fix up the GFX and SFX to make this less of an SCP Game and more of a FNaF game. :v As for Purple Guy, I can model him, but would you prefer him looking more like a human, or look like he does in the FNaF 2 and 3 minigames?