Script to insert random image into whitespace

Our company has a 500 page product catalog. We use InData to flow the products into the catalog. Our master layout uses 3 columns per page. All of our products have flexible description lengths and a variable number of children sku rows per parent item so we can’t set a specific height per item. This creates whitespace in the last column on most of the pages.

I’ve been looking for a script that can automate the process of inserting space filler images into the whitespace. For simplicity’s sake, say we have 12 space filler images, the script would calculate if there was whitespace of 1″ at the bottom of a column, randomly insert an image that will fit into that space.

Please, if anyone has run across a script that can do this let me know.