Valuation Methods and Standard Cost Calculations for Kits

How can I have Standard Cost calculated automatically from the Standard Cost of components of a Kit?  We have many kits that we build from component parts.  I know that Sage will not allow me to set the Valuation method to Standard.  I also can't figure out how to get it to update the Standard Cost in Inventory Management, based on the Standard Cost of the components.  We've been changing it manually, but that is impossible to keep up with.  I have to believe there is a utility or another work-around I can use.  Help!