But unless you make custom sway bars, you're not going to find much larger than the Hotchkis 1.25" front bar. I run a Hellwig 1.125" front sway bar AND 1.12" torsion bars, and I still don't think I'm maxed out for the effective spring rate, even running street tires.
The other issue is that if you've lowered the car, you need a larger bar to keep from bottoming out. The lower the car sits the bigger the bars are going to have to be.