2000 Volvo S80

I bought a used Volvo S80 and I recently began noticing a hollow clunking noise coming from the driver side front tire mainly when I drive over bumps and over 60 miles an hour. I took it to a Firestone shop and the y said that three things needed replacing: Bushings (both lower and front, control arm), Sway Bar link kits and Tie Rod ends (remove and replace rack and pinion boots). A few days later I went to a volvo shop to get a second opinion and the mechanic said that the bushings were cracked but fine, the tie rod ends were fine but the sway bar link was bad. I had it replaced. When I called the shop to see if the car was ready the mechanic tells me that he drove the car after replacing the sway bar and the noise was still there. According to him its the steering rack that's busted and needs to be replaced. A $1,600 repair. My question is: should I get a third opinion? The car drives fine aside from that noise though it tends to shake past 70 miles. There's no freeplay on the steering wheel. I called Firestone and asked if they noticed anything wrong with the steering rack itself when they looked at it and they said no. I also hear that its unusual for a steering rack to break. I'm tempted to believe the reputable volvo shop over Firestone but that's an expensive fix. Any thoughts?

Cheers,
Alfredo