How to show guests thread preview

[Hawkgirl]

My forums are all "members only" because it is a medical information site (infertility) and the members are really concerned about their privacy. I have a TON of CMS content (800+ articles at this point), so I get plenty of traffic. But once they land in the CMS, I want to be able to have a widget that shows them the value of the forums.
(I get 20 people register for forums for every 3K visitors ... good, but I want better. I know they want to see what the forums have to offer and I know seeing this would convert them!!)

Ideally, it would show:
x number of "most recent posts"
x number of characters from first post
hide member name
hide date of thread
show x number of characters from 1st reply

and allow me to customize:
# of posts to show
# of characters to show from first thread

How hard would this be to do? I've scoured the Add-ons and I haven't seen anything close to this.

Thanks!!