What type and size belt for bypassing the Power steering belt?

Not possible to do on that engine, that pulley is needed because of the belt routing. Without it on there is no path the belt could take and still drive the other components.
Why do you wish to remove it? If it failed, they are not difficult to change, remove the air cleaner, the belt, drain the lines as you remove them, three bolts and use a pulley tool to remove the pulley from the old one. Use the same tool to install that pulley onto the new pump, install the three bolts (torque to 18 ft lb) and the lines and fill the pump. Rotate it by hand a few times to release air. Reinstall the belt and start the engine, let it idle and turn the steering wheel back and forth a few times to purge the air out fully. It takes about an hour and a half to do. The pulley tool can be found as a loaner tool from most parts stores.

Sorry to hear that. Any relatives you could borrow from or a friend? You could likely get a used pump cheaper. What actually failed on the old one, if it still rotates you could just leave the lines off and use it as the idler just to keep the belt on, unless it sheared the shaft internally. The way GM routed the belt a shorter belt won't work because of the way the pieces rotate. Maybe a short gofund me or similar just to help for now?