You need to figure out what types of objects the arm would be picking up. The heavier the object the more expensive the arm becomes. If you limit yourself to fo

You need to figure out what types of objects the arm would be picking up. The heavier the object the more expensive the arm becomes. If you limit yourself to foam/light plastics then an arm with standard servos will work well. I would go with that, and if the need for more strength arises, you can then upgrade to high-torque (high $$$) servos. I've always had god luck with Lynxmotion (http://www.lynxmotion.com/p-866-al5a-robotic-arm-combo-kit-botboarduino.aspx http://www.lynxmotion.com/p-866-al5a-robotic-arm-combo-kit-b...). You can buy the parts separately and it will be a bit cheaper (find them on ebay for more savings).