It has already been done in the USA. At least for physical attributes. I do not know if it is possible to increase mentality the same way, It soon will not be necessary, for science will be able to correct genetic problems with specific people. (correct the genes so a person is not going to have heart problems even though both parents had heart problems) For the physical see this website
Francis Galton, Darwins half cousin was the first person to coin the phrase eugenics, and inspired by Darwins book Origin of the Species and the chapter on breeding domestic animals asked "Could not the race of men be similarly improved? Could not the undesirables be got rid of and the desirables multiplied? What do you think about this idea?
Who decides what is undesirable? It may start with trying to stop certain genetic diseases like sickle cell anemia or Huntington's, but where does it stop? Before you know it you have someone like Hitler and his master race.
Let nature do it's work. No need for custom made coz there always be screw up and nobody wants?