You're on the right track, @mb722!
Allow me to join in your conversation with @MikeinBC and share a little more information about your inventory assembly.
With QuickBooks, what you've been doing is correct. In addition, you can also create a purchase order for your inventory assembly. Here's how:
This way, you'll be able send a proposal of your inventory assembly for your vendor. I've also, included our detailed guide in creating your purchase order.
However, I'd recommend contacting your accountant. He/she will be able to help and guide you further in choosing the accounts of your inventory assembly build.
Please let me know if you have any other questions about QuickBooks Desktop. I'll be always around ready to help.