I posted the following resource information on the Warwickshire forum but this will also be useful for B/Ham KE Exam parents who are self tutoring their children for the Univ of Durham tests:
The Using English Site also contains links to some other free resources - worth hunting around.
I particularly like the free English tests available at http://www.english-test.net/
These have a series of 1 sentence online Cloze and Synonym tests with a word choice format that is similar to the Univ of Durham tests.
Worth checking out
Hope this helps