It looks like from the tiny image you first posted, that you can angle grind cut or torch off the upper part of the frame, flip and rotate and reattach to form a large chin spoiler or air dam.
Aerodynamics Photos by kach22i | Photobucket
I'm not sure what the Bullbar you linked to will be attached to. However it's probably going to be worse for aero than what you have put together yourself.
There was someone recently in the forum with a puck-up truck, which I think may have been intended for towing. They came up with a blast plate looking air deflector (semi-grill block) which they imagined would toss the air up and over the roof and trailer in tow. It might be worth looking into, for educational purposes (
not to copy), many good comments and observations. I'll post it later if I can find it.