Derrick I think the "440" is actually a 434 not that its that much of a difference.
Also from all I have seen not to say that Jerry or PCS are telling you wrong, but I have seen many ltz/kfx with the 434 kit and they are rode very hard and have no reliability issues and all the owners love em.
Just my  if it were me I would get one with no worries just do your research and see which kit is best.