Since you already have the steel brackets from The Parts Place, all you need is the aluminum piece pictured in post #12. It's common to 68-70 350 and big block A body's. It should not be a hard part to locate.
Water pump has nothing to do with ps brkts. PS belt is driven from the crank pulley. Also, all A-body models use different PS brkts. Get the 71-2 Skylark ps brkts and you will be set. Those are more common, looks better with the ps pump lower and the brkts are much cheaper.
Scott, No, they do not. The full size will let the ps pump lines contact the steering box. The 71-2 Skylark brkts keep the lines about 2 inches higher. To see the differences in the brackets, see : http://www.buickperformance.com/ps.htm
DRS4554 that may be true, but I also needed a steering box as mine was leaking, as well as the pump and brackets. So I needed more than just brackets and felt my best bet was to get a complete system, which I did from BrunoD. So I got new brackets that are not complete, I got another pump that only had the front bracket but not the rear and were a different style than the first brackets and of course no mounting bolts for either. :rant: So I just got tired of getting pieces that don't work together and got a total 'kit' from a 455 Skylark with a long shaft WP. Finally it should ALL just bolt up and make me a happy camper. The 'kit' should be here in a few days and I'll add an update then. I had no idea there were so many combo's to make all this stuff work together. :eek2: