Both are polyethylene, and as such on the heavy side (75 lbs for the P164, 87 lbs for the Disco 158). The P164 is a couple of inches longer, the Disco is a couple of inches narrower. The molded seat pan and back rests in the Disco would be problematic for paddling bow backwards.
If you have a strong back and don’t intend to carry them far either one would offer plenty of stability for fishing, and initial stability can be enhanced by altering the depth of the seat drops.
I doubt that the P164 is easier to paddle (the Royalex Penobscot 16 would be far more efficient if initially “tippier” feeling). For a novice first canoe and semi-stationary pursuits like fishing the differences in efficiency between the P164 and Disco 158 are likely negligible.
