Here's a thought. Why not have high-experience folks each take a newer programmer under wing for this project? That makes it an opportunity for the more experienced people to get a feel for teaching, and the less experienced people the chance to benefit from wisdom and having-previously-made-mistakes.

If I were to mentor someone, I'd let him do most of the work, but offer suggestions and ideas when necessary. Seems like each pair could take a module or a chunk of code and work on it that way.

Or I'm a huge idealist. Either way.