[development] custom notification system

I'm working on a system developed in drupal. In this system create trophies to be assigned to users according to the behavior of these in different ways. Trophies will have categories related to aspects. I need each time you create one of these categories will send a notification to the user webmaster and this will give permission to be believed or not the proposed category. The problem I see is that all these modules I created without using precisely the nodes in drupal, I mean, use separate tables, and I think that the application of the actions and triggers will not adequate as i need, using the hook_nodeapi. Someone can give me any suggestions on how we could create a notifications system that meets my expectations?