The problem with the floor bar and C-pillar bar is that there really aren't a lot of forces acting at those points. Think about it. The strut top is what pushes against the strut when you hit a bump. That's why you put a bar on it to brace it. What forces are acting on your C-pillar? Raising the hatch!? What will the floor bar brace? Hitting poles? I'm not going to deny that there are some deflecting forces at work at those points, but the actual deflection is so small that you couldn't feel it by the seat of your pants.

If strut bars aren't enough for you, swap the rear for a Cusco triangle brace and add fender braces in the front.