It's all trackable, including using the specific item on Sales Orders to manage reservation dates, as long as you get higher than QB Pro. For Pro, you would use Estimates, not SO.
Running your equipment rental business with QuickBooks can be very beneficial from a financial and accounting perspective as the customization of reports and ease of use is really second to none. However, inventory tracking for rental or (service/non-inventory) items is a bit tricky and requires a lot of work around and double data entry if you try to do it directly in QuickBooks.
Instead you may want to consider an add-on software/plugin to QuickBooks that uses the service/non-inventory items on your invoices to track when those items are scheduled to be out of stock (or "rented") and when they will become available again. One such product is https://adelielogistics.com. You can check it out and hopefully it helps accomplish what you're trying to do with QuickBooks.