I am working on a smf bridge that would be for whmcs. If your interested in a smf bridge for whmcs, you can feel free to fork the project on github. For those not familiar with the whmcs licensing scheme, although it is closed source, they do allow the creation of bridges through addon modules.
https://github.com/XAOS-Interactive/SMF-Bridge/tree/master
http://docs.whmcs.com/Addon_Modules
Good luck with this. WHMCS needs a good bridge addon. I used the forum addon for about 2 months, and found it lacking. I also submitted two support tickets and it's been over a year and still haven't heard back from them. If you make this, you'll probably get quite a few responses.
Hi,
How is this going, as I maybe looking for a SMF WHMCS Bridge