Welcome to Geo-Ship!
A simple search on multiple eBay sites.
Use searches notifications with different intervals (4,8,24 hours)
Select multiple eBay sites from advanced page to search all of them at once
Saved searches will be saved forever if you save them while logged in
Make use of primary ('eBay sort order' from advanced page) and secondary (search results page) sorting: For example: search items by 'best match' and then sort them by 'seller feedback'