I think it depends on what your goal is.
The "approved" version for the PCUSA is the NRSV, which is what we give to our third graders.
If your church gives Bibles at Confirmation or another time, that should be taken into consideration.
I have really liked the New Adventure Bible for Kids to use for class rooms.
There is also a new version for children in the NRSV published by Abingdon- the NRSV Children's Bible.
I would recommend taking a trip to your local Christian book store and looking at several options- then you can see what seems like it would work best for your church.