The BaseRails site uses the acts_as_commentable_with_threading gem, which is very easy to set up. You'll still need to create the scaffold for each forum topic, but this gem will allow users to create threaded comments on each of those forum pages.
Here's the link to the gem page: https://github.com/elight/acts_as_commentable_with_threading
Thank you Alex, I'll give it a shot installing the gem!
I've got it to work thanks!