Chef, do you mean stitching awl?
There are a couple types of needles. The ege eyed harness needle is the one used for stitching with a awl. It has a blunt tip and will follow the hole made by the stitching awl. This is the one used for most sheath work, size depends on what thread you prefure. Al Stolmans book Stitching Leather is about the best for getting you started.
The glovers needle is sharp and pirces it's own hole, mostly used on thinner soft leather.
The stitching awl is a two part purchase. The haft or handle and the awl itself.
The awl has to be polished in to work it's best. Also helps to have a stitching horse of some sort.
hope this helps, RS