whats wrong in reconditioning the head with new valves, guides, seats (if required), seals and good cleanup??
the key to longevity is following proper procedure, e.g. facing the valve on the seat, if your face margin is less than 2mm wide and only has one level of cut - they wont work for more than a year - even less if you GUN the engine dead cold. If you install valve seals without protective sleeves on the valve stems you will tear the seals. If you dont pay attention to the guide reaming your guides will wear out shortly. Or if the guides are not chilled before installing.
Its not alien, you can get a proper lathe machinist to follow these instructions, for chilling the guides ask a local "rehri kulfi waala" for some "qalmi shora" if you cannot find some raw dry ice.