Yeah, you should be able to do all that stuff yourself for nowhere close to $400. The fuel filter is a bit of a pain, the first time I did mine I didn't have the gasket in just the right way and fuel was spraying everywhere. The fuel filter is near the middle of the engine compartment mounted on the firewall. You will probably need to unbolt the vacuum unit from the firewall to get to the fuel filter. But it's do-able. Yeah, hopefully your wife meant valve cover gasket. I don't see what a new valve cover would accomplish unless it was damaged in some way.