I used Hooker Competition headers on my race cars because back when I was racing they were made equal length and bigger to allow a bigger motor to breathe better than other brands.
Today they are all alike (made by robots to almost but not quiet fit the car in question) with a Headman header not made to race but to fit in your car better than a Hooker did. I used Headman's in my shop because it made my job of installing them easier than a Hooker that often required denting tubes to get it to fit.
Today's header brands are not only all made alike, often it is the same set of tubes with a different label on the them because they are all owned by the same company. For example Holley owns and sells both Hooker and Dynomax brand.
Back in the days that I was racing Bob Headman had a muffler shop when he started making headers in 1954, Gary Hooker was a businessman who saw how headers sales where going and stated into business in 1962 designing headers for his employees to weld up, Doug Thorely had a muffler shop that sold unique design idea to make more power (torque) on the street that still works today; he started selling his Tri-Y headers back in 1958. All of these guys are long gone having sold out decades ago with only their name having anything to do with headers. Today their are still custom headers to be purchased made by hand the old way; but even they are not one of's but a copy of one designed by a welder who fit pipes to a car body similar to your car.
I buy a header kit and take it to my local muffler shop and have the kit welded up by the muffler shop's welder (it is made of stainless steel needing argon inside and outside of the pipe to be TIG welded by an experienced welder that can get into tight areas). I pay the same as a set of Lemmon's headers but they are going to fit my car like a glove and are complete from the head to underneath the bumper. You can save money by buying a mild steel kit but what you are mostly paying for is labor, so a stainless exhaust will never rust out.