When I first started sewing leather, I used the needles included in those Tandy kits... Broke every single one within 5 stitiches. Switched to harness needles, and have never had a problem since. You can drive em in like nails, and they won't break. The only time I've ever broken one was when I tried intentionally to bend it, and it broke in half, not at the eye.
You can get them in different sizes, but the smaller the needle size, the smaller the eye, too, so you need to use thread size to match the needle eye. Made a big difference in my hand stitching now that I have choices other than that "rope" thread that Tandy sells
I've also tried glover's needles, but they were too sharp, and if your aim was off the tiniest bit, they'd stick in the edge of the hole.
Glover's needles do work well with thinner leathers, though, such as garment weight.