I had the armstrong steering on my 1 ton, and had no problems. Then in the process of a disc brake install I ended up with power steering too... And it's great, you don't know how nice it is till you have it. The truck was not that hard to steer before, but now with the truck sitting still I can put one finger on the rim of the wheel and turn lock to lock, no comparison.
If you are creative you can drive the PS pump off a second belt grove on the generator pulley:
http://rides.webshots.com/photo/1484182686080251109emAXqyGrigg