I don't think there is a good way to put rack and pinion on a straight axle. If that is what you are trying to do you have a tough challenge ahead.
The problem is unless you mount the rack on the axle you have a bump steer problem, but if you mount the rack on the axle you have increased the unsprung weight, plus you have a challenge connecting the steering column to the rack.
If you want IFS but object to using a Ford product, you might look at doing a front clip, or a Jag or Corvette system.
