bestmapman - I don't think that the front "boattail" is really neccessary in your situation. If the ideal aerodynamic shape is a teardrop, then you'd want the front of your car to, basically, be blunt. I think that something like Autospeed's front undertray and wheel spoilers would be a great starting place for the front.
As for the rear, your photoshopped version looks excellent! No complaints there
