If you are looking for bonafide JWs to debate on-line, you may be a lonely guy.
You see, the internet is demonized. It is filled with apostates. It is evil.
The internet has been discouraged by the Watchtower Bible and Tract Society from the beginning. Web sites for and by actual JWs have been strongly discouraged, and in many cases closed down by threats from headquarters. I personally know a pro-JW site that shut down when the owner was told that he would be removed as a ministerial servant unless he closed it. There are almost none left.
The reality is that JWs doctrinal system is pretty fragile. When they knock on a door, they rarely get a knowledgeable response, because they are unexpected. When they come to the internet, they run into people who are qualified to refute them. They are greeted by people like you (who know your doctine), or us (who know their doctrine), and they don't last very long.
A JW on the internet is usually a soon-to-be ex-JW.