inventory

A client has asked me to build them a sort of 'inventory system', and I would like to build it using Drupal rather than writing a custom solution for it. However, there are a few things I would like to get some dojo feedback on.

These are all tasks I could do if writing the site from scratch. However, I want to do it in 'the Drupal Way' and take advantage of as much of the existing Drupal infrastructure as possible, so I would appreciate any advice on ways to best do this in Drupal.

Structure

The first challenge is in the structure.