Would like a locked form that my team can fill out

We produce catalog pages for a yearly rights guide, and we aim to have two items per page as you’ll see in the attached. Looking for a way to lock in specs and length so that when someone inputs copy, it doesn’t allow them to write so much copy that it pushes the second item to the next page. So would like entry points for different copy in the different spaces, each with locked specs, as well as space for a book cover, logo in footer, etc.