Hellz, that's pretty much wrong on every level.
Anyways, there is a way with Quake 3's code to have different player models; just look at Quake itself, you can choose a model.
This has been proposed for Trem, but would require changes in netcode, some pretty serious client-side changes, and would require new models be made to be used.
Overall, it was decided that it was too much work, and nobody has done it yet.