There's a 'sinister springtrap' character available via source film maker. It can be imported into blender or de/re- compiled using 'gmod add-on creator'. I've spent a few hours on it but I can't produce a .GMA that loads into Gary's mod.
If your .GMA loads as a ragdoll in gmod, the Job's done!
I'm seeking a price at the lower end of the range shown.
I don't want to overhype this part, but I have more piece work (CCTV, linux admin, wordpress, social media, adwords, other marketing....) from time to time for a sensible generalist, I'd be interested in a longer term business relationship.