Dont forget to check that a sway bar will actualy fit! On the AE82 model corollas, only the hatch shells had the chassis mounting points for the sway bar. Sedans don't.
I'm not sure abut the different versions of the AE92, but its worth checking before buying!
Bigger may well be better depending on what you want the car to do. A sway bar will not help if there is a problem with the suspension setup in the first place. Best to talk to a suspension expert about how you want the car to handle before buying parts.