Porting an existing YaBB SE forum database to Drupal

Hi everyone,

I was wondering if any of you could help out...

I am currently using an old YaBB SE forum with a rather big database of posts that I would love to migrate to the new shiny Drupal installation I have set up to catapult us into the new millennium and finally move away from our ghetto with a real CMS system. I do not want to integrate the YaBB SE forums to our site, just port the content itself.

Call me crazy, but I must be one of the few that like the simplicity of design of the Drupal inbuilt forums (even if I intend to mod it quite a bit in the end)...
However, I am sure some of my moderators are going to be screaming bloody murder so I was also wondering if any of you could help point me out to some places where people may have developed small functionalities (like enabling splitting of threads for example) or presentation (better Quote differentiation, separations more visible between posts, etc) enhancements for the core Drupal forums.

Thanks in advance for the help!

Cheers,
Mathias