Stroker, I researched the subject as well and ended up going with the AGR box. It's a really nice piece.
I called up the Summit tech line and the guy couldn't answer all of my questions so he gave me the AGR tech line number. I called and talked to one of their guys - at length. He was really nice and knowledgeable.
He ended up recommending their variable ratio box (13-17:1). They also have a straight 12:1 box (both for power steering), but he said that it would be a little "twitchy" on the street.
I just told him that I wanted to get the part number for my application ('67 Chevy SWB pickup). He gave it to me and I promptly ordered it from Summit when I could get their discount (last month). I haven't installed it yet, but I can't wait till I get it put on.
I'm probably going to put one of the Type II pumps and a cooler on it, since I have aspirations to take the truck to the Silver State Challenge in the future.