I am wondering if it would be possible to create variants of a particular sales item which would include another item in it, sort of like a bundle. Let me explain what I mean. So, let's say we are selling a machine which has two variants of power supply (single and three phase). Now, when we purchase the single phase units, they come with an external power supply box which is several hundred dollars. They are visible on the purchase invoices we receive from overseas. When we sell these machines here in the US, we could just indicate the variant of the machine (single or three phase), and then the additional power supply would be automatically taken off the stock but the machine and the box would still be visible as a single item on the sales invoice and have a different price. Is this possible? Or do I have to put two separate items on the invoice? Another possibility is to simply increase the price of the single phase unit by the cost of the power supply box and perhaps not even adding this to our inventory when we are purchasing it. But the ideal scenario would be if we could create two variants of the machine and in case of the single phase units, the power supply box would be automatically taken off the stock and the price would be automatically adjusted and the box would not appear on the invoice and would be an integral part of the machine. What are your thoughts, could this be done?