native cs_set_user_model(index, const model, bool:update_index = false);
If true, the modelindex is updated as well
Sets the client's player model.
This is not a one-time set. The CStrike module will remember the
selected model and try to prevent attempts at changing the player
model, or immediately re-apply it if necessary.
Updating modelindex is useful for custom models which don't have
the same structure as the default ones (hitbox, etc..). Model must
be precached before.
This function has no return value.
If the client index is not within the range of 1 to
MaxClients, the client is not connected, the provided
model is empty, or if modeindex is updated and the
provided model is not precached, an error will be thrown.