After years of owning lifted Chevy's I've just come to the fact that you can't turn the wheel while sitting still. I don't think it's a good idea to even try and turn it if your not moving. I've found out that it is very hard on the steering parts. You will wear out the idle arm, pitman arm and tie rods faster if you crank the wheel while not moving.
If your looking for a better pump I would try AGR but i've never looked into it that far. I would look at their web site or give them a call. Your gonna pay for it though. They don't give those things away.