I'd use phpAdsNew to manage the banners.
You can define a categorie in phpAdsNew for each board. Apply the correct banner to the category and simply reference with remote invocation.
Make sure that you also use the categorie name of threads as the category keyword in phpAdsNew.
If there aren't any buttons/banners in the category, a default banner or simply nothing can be displayed.
Of course, phpAdsNew tracks all the views, hits etc. of the buttons which might be interesting for your customers also.
