It's not really a matter of which is "better". The best sway bar is the one that has the correct rate for the rest of your suspension set up, so that you get the effective wheel rate you need. Hellwig sells a hollow 1.125" front sway bar (that I run), Hotchkis sells a hollow 1.25" sway bar. QA1 has also recently released a 1.25" hollow front sway bar https://www.summitracing.com/parts/qa1-52861/overview/year/1974/make/plymouth/model/duster, which conveniently costs less than a Hotchkis front bar, but more than a Hellwig. FirmFeel sells a 1.25" hollow front sway bar as well, it actually costs more than the Hotchkis bar does.
Ideally, all of these companies would just publish the rates of their sway bars (none of them do). And the larger diameter bars aren't necessarily stiffer, because these are all hollow bars the stiffness depends on the wall thickness too, which also isn't published. Bigger isn't always better anyway, you want your wheel rate to be correct for the rest of your suspension set up. If you run really big torsion bars you might not want the stiffest sway bar available because your wheel rate could end up being too high. If you run smaller torsion bars you might want the stiffest sway bar you could find. And if you run crappy tires, well, you probably wouldn't want a whole lot of sway bar at all. Just depends. I picked the Hellwig bar because I couldn't see paying that much extra for the Hotchkis bar for an 1/8" outer diameter difference, especially running 1.12" torsion bars already.
Here's a decent article on sway bars. They actually cover how to find what the working rate of the sway bar is on your car, which is even better than just having the calculated rate because even sway bar bushings can change the working rate. Realistically though, unless you're competing for time at a high level, any of those sway bars will probably be just fine.
Sway Bar Rating Techniques - Circle Track Magazine