What do you intend to use the plane for? The shorter the sole of the plane, the more difficult it is to plane something flat and true. That's why smoothing planes are bigger than block planes, jack planes bigger than smoothing planes, and jointer planes bigger than jack planes. Each one makes a line progressively flatter and more true.

Part of the key to getting good fitting strips it to be able to make straight lines, so a longer sole is a good thing. If you have physical limitations and can't hold a standard block plane, then maybe look into a smaller block plane like the standard Stanley low-angle block plane or the Veritas apron plane. I have both, and they are my go-to planes in nearly all situations (stanley for rougher work that might "mess up" the Veritas). I have a standard size block plane as well, and other than that the workhorses in my shop are a 4 1/2 smoother and a #8 jointer. I also have small model-makers planes from Veritas. They're super specialty planes at least in my work, even when doing intricate work like making violins. If I need a shorter sole than a block plane, I usually use a spokeshave.

If I were going to choose one plane to build a strip kayak with it would be a hard choice, but I think I'd go with the Stanley low-angle block plane.

m