If you can trick them into clicking something in an email, you can send them a link to any page that you have access to the webserver logs for and find the request in the log (along with their IP). There are also a number of third party services to do this for you that are pretty easy to use (eg http://whatstheirip.com).
Now, that said, some of the scammers out there are highly dangerous individuals with organised crime connections. Think twice before tangling with these people and consider the value of the money you've lost vs the potential cost to you and your family if they decide to try and hurt you. These people may be quite comfortable resorting to murder or kidnap to get their way, do you really want to move out from behind a computer screen and face someone like this in person?