You could duplicate a listing and change it's country in the Advanced inspector.
If you are selling the same products over and over, it might make sense to create inventory items for your products and then create site-specific listings from those inventory items.
If used correctly, once you decide to change a products description or images, you would only need to the edit the inventory item, and all linked listings should update accordingly.
Unfortunately, because of the way eBay is constructed, you would still need adjust pricing, attributes, shipping and payment options on the listing level.
Hope this helps.