If you have very little for props and costumes it's nice to do something that you can get creative with - like 'Wizard of Oz' or 'Alice in Wonderland'.

MTI has a bunch of new shows for younger players coming out - and many of them you can get the tracks to.  Also check out the 'Jr.' versions - they're pretty good.  MTI is updating all the time so make sure you go a lookin.  

Joe and the Amaz. Dreamcoat is THE childern's muscial staple in Athens, Georgia and has enjoyed wild success here.  One run I was in with the local community theater did so well that a special encore run was performed the next season.  The high school here also did it last year, as did the children's theater camp.  It can carried off with great charm and aplomb using very limited resources and a cast of thousands--bare suggsetion of set and costumes can work very well.  The theater camp used a single piano for accompaniment.  However, I do think the play's success largely hinges upon a strong, charismatic leading male, and if no such person readily presents themselves to your mind, I would seriously reconsider.  

Although there are 12 brothers, there is really no rquirement for all to be on stage.  In the scene where the brothers identify themselves, only two "brothers" named the others vollying as if in a tennis game.  In the "Caanan Land" scene, two brothers were playing a table game, much like checkers, while two other brothers watched, bewailing their fate. 

The director used imagery to make you forget that you were not getting the full number of brothers.  Using sketches and blackouts, with lots of high intensity dance and music, you were so drawn into the story that you forgot the size of the cast.

It was an outstanding presentation of the story in a totally unexpected way.