I don't think they'll fit. It'll be cheaper to buy new ones, which you can get for under $100 both on Amazon https://amzn.to/4apIBZM
Look around, maybe even cheaper.
Might be inside the rack and pinion or a sensor. Any lights on the dash? Check this gm article out https://gm.oemdtc.com/4286/loss-of-electric-power-steering-assist-2007-2012-chevrolet-pontiac-saturn
First try to find out what they fit but because they are 20 series and low profile, I would try to get $150-250 each so $600-1000 as long as the rims aren't bent or damaged.
I'm surprised you are having so many issues with aftermarket axles. Vibration and shaking is usually caused from the axle being out of balance. Try rockauto and carid to see how much the axle is. Also go to a carquest store and see if they can get you an axle from worldpac which will be like OE but cheaper.