Fylnn, have you checked the bump steer of your car?
They do have some bump steer in standard form, but it's not too bad. What you are suggesting would cause a very big change to the bump steer characteristics of the car. The correction to fix the bump steer that the standard geometry give would be measured in millimetres and needs to down, not up by 30+mm.
If you use Vin's long shank top ball joints, the outer tie rod end needs to go down some more, but not massive amounts. When I get to doing the bump steer correction on my 75 that uses Vin's ball joints, I'll post what it is I've done (it will be based around drop links (as opposed to my first attempt of bending the arms) and uses spacers to lower the outer spherical rod end. Drop links are 4140 steel and work with the 5/8" rod ends I've got, but are designed for Mustang steering).
And finally, you won't find a spherical rod end with enough articulation if you raise the ride height by 50mm. I've got some high articulation angle rod ends and even at a slightly lowered ride height, when the suspension was at full droop, I didn't have enough articulation. And that's before correcting the bump steer (moved the rod end lower and so needing even more articulation).
The only way you could use a rod end in you proposed situation, would be to twist the steering arms so the rod ends don't bind up at full droop.
http://www.youtube.com/watch?v=LO07qmJ9zkk is the best way that I've seen to measure bump steer. It's also incredibly cheap to do.