Paintball at Adventure Camp

No, this is not quasi-military "stalk your friends through the woods" paintball.  The Guide to Safe Scouting expressly forbids that kind of fun.  What we are adding to Adventure Camp in 2013 is target shooting with paintball guns for rising 5th graders, also known as Webelos II's.  We like to call them Arrow of Light Scouts at Adventure Camp.

So, we will be investing in some paintball guns between now and June.  Any suggestions on what kind of paintball guns we should get?  We're looking for paintball shooters that will last at least 4 or 5 seasons, are easy for 9 and 10-year olds to operate, have high marks in the safety department, and won't blow our budget sky-high.  If you are a paintball aficionado and have some advice, please bring it on!