For versatility a simple (but quality) visual ghost boy would give you possible pastel ghosts plus the option of using him to produce diferent hets form other females for longer term projects. A better option, IMO, would be either a hypo mojave, which would be a stunner in his own right and directly give you the chance of more hypo mojaves, pastel orange ghosts (POG's) and pastave ghosts. A POG male would give the chance of more POG's and SPOG's; both would obviously give hets too as all babies they sired would be het for ghost.