You're still going to run in to the same basic problems. The packaging is as such that the rack ends up typically being forward of the steering arms and either above or below the lower control arm pickup points.
Here's the underbody of a 63. Pay close attention to the relationship of the inner tie rods and drag link to the lower control arm mounts. Then also notice where the steering box is, in relation to the pitman arm and it's pickup with the drag link.
If you decide to go with a rack, there's going to be some fabrication here. What I would do, is cut out the forward ovoid portion of the cross-member and box that in. That would allow the rack to be mounted so that it is inline with the steering arm. You would then need to size the rack properly so that its tie rod pickups at the rack are located in the same position that the inner-tie rods pickup the drag link. If you can achieve that, then you just need the proper length tie rods for each side and you should attain nominally the same geometry as the factory steering system.
What you will likely run into is that the needed length of the rack is fairly short, which limits steering angle and turning radius. You may run into packaging issues with the column as well, depending on if anything gets in the way of the steering shaft you'll have to build. Although I suppose it's possible, the rack out of a Prius is probably not the correct part as much as it's simply easy to acquire. I would instead be looking at circle track suppliers who can build a manual rack to the specifications needed.