I was not replying to you. But to answer your question, the most you can do is set other class models over the spy, and then change the spy's weapons respectively. A custom plugin would need to be written for you in order to achieve what you are wanting.
then why can this plugin give like a scout the dead ringer but you cant activate it BUT if you give a scout a splendid sheild it works...from certain keys like R+RMOUSE