Ron Alexander started the Ghostbusters rival company, Ghostsmashers. He also developed the uniform and equipment for the team.

And the thrower. It bares a striking resemblance to the Nintendo NES light gun

These are just a few ideas for props you may wish to replicate from the expanded universe but there are many more. Please remember that visibly cardboard props will not meet with clearance. As with any prop, take time study your references, think carefully about the parts you may need. With replicating something from a comic or cartoon, get creative in thinking what certain parts resemble and try them out!