I had a leaky steering box too. Found all the how-to info in this forum. Whunter had excellant info and step by step. Changed it myself. I found a shop on Ebay and purchased a rebuilt with a three year warrenty from CarSteering.com. Free shipping too. And for $12.00 more I got a UPS return label to send the core back.
These people are great. And the steering box comes already centered. Makes the car respond much better.
I also recommend replacing the steering coupling as good measure. My car had 231,000 miles on the clock and the coupling had a couple of good cracks in it. Look in the DIY section of this forum to see pics of a bad coupling. Good luck.
