I would be very helpful if we could see all options and categories when adding inventory to an invoice as a line item, rather than having to type it first for it to auto-populate. Sometimes services or parts can have synonymous terms that weren't used when creating the inventory listing, making it difficult to remember the wording used for the item.

For example, OS Reinstall can also be called Reformat, and so on. Most POS systems have a visual aid that allow you to see what is in the inventory. This would be ideal.