Tom,
Just another opinion from the peanut gallery, I recently changed to a Lexan front windshield in my G Prod car. There was a major debate as to where to locate the required 3 interior braces, with strength, and visibility as the 2 major considerations. As usual, there were numerous recommondations as to how to space them apart, and how close to the drivers field of vision they should be placed.
After all was said and done, placement only affects your vision while driving thru the pits/paddock, and very little at that.
Under race conditions, you are looking so far ahead, or behind, that the braces or bars simply disappear from sight. I don't know if your brain replaces what is blocked, or what, but it still gives you a full view of what's there.
I have 3 two inch retaining straps directly in my front windshield, and at speed, do not see them at all. If you are looking at your windshield, you are not looking far enough ahead to see what is going on in front of you, and that's not a good thing!
Put your bars in your cage where you think they will add to your safety. The visibilty factor will take care of itself.
Just my 2 cents.
Good luck with your new project!
Mark