Young Simon Templar
Here's a thought...my eldest son has recently discovered both Young James Bond and Alex Rider (he's only 7, so I'll give him a year or two before I let him discover the Saint).
Of course, I couldn't miss the opportunity to read the books either and they got me thinking. The Bond books in particular are rather splendidly written; Charlie Higson has done a superb job of taking Fleming's character to Eton and shows an excellent understanding of how to put together a Bond story.
Would a Young Simon Templar work?