Oh thanks for the quick reply Chris!
Ah true, so the solution I am trying to create are kind of two-fold.
One, we have some related products on some pages, and there has become need to relate more types of content than what we had by default.
Two, I am also working on a new related products widget that allows us to relate tagged content or various content types. The tagged content should be easy enough, but relating specific items from multiple types would be the new thing.
Yeah the ID's of the content is not a bad idea for a basic related field. I don't think there will need to be reciprocal relationships, but it might be wise to attempt and set it up that way for future possibilities.
What are your thoughts with those solutions in mind? I might wind up doing a simple and complex version of these to fit different use cases... still not sure yet.