I've always liked the smooth transition of the four primary tubes on the Hooker headers as they go into the collector, (as you can see in the pics of post # 4 above^^). Does that really equate to more power, and better exhaust flow than an abrupt transition like the Hedman headers have?? I don't know. I once had Hookers on my 70 Chevelle, but since I have a tall deck block, any off the shelf headers were going to be a big problem with fitment regardless of who made them.
I've heard good things about Doug's headers but I never had them myself. I'm not even sure if they're still in biz. Ya never know these days.