Put the driver side header on, you'll figure out right away where it goes if you need it. Later down the road you'll find out that the best way to install them is whatever way they land in the garbage can. Put the old bracket away in a safe place, you'll thank yourself later.
The won't-bite-you-in-the-ass-later route is to return the headers before you ding them up, and buy a pair that doesn't require the bracket. Paying more for good headers is cheaper and safer than broken power steering components down the road.
Oh, and a search for "headers power steering bracket" yields many results.