4
2 Suggestions to make:
1 - Use the hacked Phpbb from www.bbpixel.com
This will allow you to link an existing phppp with Xoops, but the only issue with this - the module needs to be updated with each XOOPS release.. and security fixes are not so easy to make.
2 - Convert the data to CBB - XOOPS native forum.
Theres a convertor on www.xoopsforge.com (home site for CBB). Although it's slightly different from phpbb - it's a module written for Xoops, and therefore wont need hacking to get to run.
If you use the convertor, you'll be able to move users across to XOOPS and posts etc...
As ever, please make sure you backup everthing before use (data and site...!) and in this case, i'd recommend testing the conversion locally on something like XAMPP
