I have an extra steering rack laying arroudn when I did my Pedders upgrade in the summer. And I wouldn't be surprised if you couldn't buy just the part.
I went though the same thing when my wheel bearing failed. Couldn't get just teh bearing, GM only had the whole hub assembly for $500. I ended up finding some probally crappy Chineese one that had the ABS sensor and all for $100. No issues but its only a few months old also.
2003 Corvette Z06 - MGW shifter, Corsa X pipe, Corsa Xtreme exhaust, Texas Speed long tubes w/o cats, PowerStop rotors/pads, Conti DWS tires, C6Z51 F&R sways, C5R headlights, tuned
04 GTO - sold