See reviews of tilt/shift lenses in DAP.
When making composite stitched images (see the Alpine Creek example and others), besides the challenge of optimized focus given the field curvature and focus shift behaviors of the Nikon 19mm f/4E ED PC-E, the other challenge is avoiding parallax. Which of course applies to all shift lenses as well as rotational stitching.
When shifting, the front of the lens moves, that is, the portion that contains the entrance pupil. The shifting operation translates the position of the entrance pupil by the amount of the shift. Thus there can be up to a 25mm of dislocation of the entrance pupil, which creates substantial parallax at close range. Parallax is problematic for shift-lens stitching just as it is for rotational stitching.
Below, gear I use. I have most of this stuff, and the newer items like the Really Right Stuff Multi-Row Pano Package I expect to have soon for evaluation.
Clamps require the correct mounting screw (M6 or 1/4"). The clamp on my favorite head (the Arca Swiss Cube, see review) is dubious and should be replaced with a Really Right Stuff clamp like the B2-Pro-II.
Not all items shown since some might not be available in feed, see links above