Yes, a 98-99 Durango steering box will fit a 1997-2002 TJ.
I just ordered a Fenco steering box from advanced auto, part # SG17917. It's a remanufactured Dodge Durango, non-Plow '99. I can confirm that during install it was a bit beefier than the stock box on my '99. I did not have to do any modifications to the bumper but it was a tight fit. If you order through advanced, look for the online coupon codes to get $50 or more off the order.
Someone mentioned that the snow plow version has quicker steering and my understanding is that this is incorrect. The non-plow version has a gear ratio that provides stop-to-stop turning in 2 15/16 revolutions of the steering wheel. The plow version, and the stock TJ box do it in 3 3/8 revolutions, making the non-plow a slightly quicker turning box, but this does not result in tighter turning radius! The quicker turning reportedly is not detectable in everyday driving. I maybe have noticed a touch more sensitivity now that I have the new non-plow steering installed and everything aligned properly. [Sauce:
97-2002 Wrangler Durango Steering Box Upgrade/Swap - The Destination Jeep Forum
With the right tools (pitman puller and a big wrench for that nut holding the pitman on) it's a pretty straightforward bolt on affair and should take the avg Joe about 2-3 hours.
~Chris