Can I ask what they have found wrong with the rack? Usually they don't give too much trouble. If it's just some wear in the Nearside outer bush then you used to be able to buy a kit to overhaul them.
Just replaced one on mine, cost about a fiver here in france, you can get new racks on www.oscaro.fr for about 100 euros if it's dead. Wind it out fully to the drivers side and see if there's any play, if not then it's fine. Pm me if you have problems finding the kit, I'm away for a few weeks but could get you one sent out in feb.