You could also consider one of these:
http://www.optcorp.com/product.aspx?pid=30-718-78-11589
It zooms from 8mm to 24mm by rotating the top of the eyepiece, I have one and it is better quality than the celestron plossls I have, and you get such a range of magnification in a single eyepiece.
I find it absolutely great for the kids as they can find things easily at 24mm then click and zoom in on the object without having to change eyepieces.