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I'm not sure how to achieve getting the stats displayed on your home pages. For now though, I would wait before making a major move. The newBB is undergoing changes and may have more options to help you. Also, once this is done, koudanshi (maker of phpbb and IPB mod fo xoops) will have to revise his system, so I don't recommend doing anything untill thats been sorted out.
It may very be that your best option is just provide a link for the sake of saving your users the hassle. The options available for XOOPS boards are limited right now, but hopefully that will change.