In a couple of weeks we'll be putting a new book table out at church. Some of our favorites this time are these two by Ed Dunlop - The Quest for Thunder Mountain and The Golden Dagger. These books are the first in a series called 'Tales from Terrestria' and come after the 'Terrestria Chronicles' which are also excellent books. These books are really clean and are allegories that even I can understand. Your kids would love them! They don't have any "fantasy and wizardry" you might find in other allegories.
Another set I really enjoyed, (I proofread them for the library), is another set by Ed Dunlop called 'The Young Refugees'. It's a trilogy that takes place during WWII about a brother and sister. These also are really clean and the gospel is presented clearly which I really appreciate. Both of these sets of books can be purchased at http://www.talesofcastles.com/ Have a great evening!