This is still in development so expect bugs such as missing animations, features and other broken shit.
This is the Sandbox gamemode but with more playermodels such as GMod and a few other custom ones.
To change your playermodel, hold G and select from the menu.
This also has uncompiled assets at the GitHub repo so feel free to edit or use them for other things.
https://github.com/randomperson189/sandboxmorepmdls