I just ordered a "AGR Super Pump" pt#877257 from Summit Racing. I wanted to get the rock ram kit that adds a hydraulic ram but it was out of my budget. I talked to 3 different people that have just replaced the stock pump with one of these. They all had very noticeable increase in powersteering and good reviews. The pump is not much to look at, so I hope it works better than it looks.
I talked with AGR before I got the pump, they really recommended the "Rock Ram" kit which comes with an upgraded pump, upgraded power steering box and adds a hudraulic ram. But you also have to change your pitman arm as well. They said its not a bad idea to replace the hydroboost to a specially ported unit as well, but they said that was not required. If money wasn't an option the Rock Ram kit is the way to go. I talked to several guys from Moab who build rockcrawlers and they say you can one finger turn aired down 44's with the diff. locked, no problem.
I will try to post my results after I get my pump installed, hopefully this Sunday.