Connecting items in from webshop A to B

In the current project I'm working on we need to connect items in different webshops together. These items are the same but they have different article numbers and different descriptions so the association between the two needs to be done manually by the user through our interface.

What would be the best interaction for the task? Are there any best practices from other applications?

My initial idea is to utilize drag and drop. The user would drag items from B to A and thus connecting the items. Although the interaction is intuitive it may be time consuming and straining so I would also also like to have a faster way of performing the task for advanced users.

For novice users: drag & drop.

For advanced users: ?

Any thoughts and advises are appreciated!