I’ve used African Blackwood, Katalox, ziricote, real royal ebony, brown ebony, macassar ebony stripped ebony, white ebony (sap wood) and Indian ebony. They are all lovely woods, but there is something about jet black Gabon ebony that holds it dear in my heart.
for splitting, I’ve made about 50 of these over the last couple years with no negative feedback. I only use kiln dried gabon ebony and work it slow. I did get some wetter ebony - cut and drilled it, let it sit for a year before using.
The only issue I did have (which caused me to replace the handles free of charge and give a partial refund, ouch) was early on. I did a couple handles that had nickel silver and wood endcap. The end cap fell off after a few months where the nickel met the ebony. The nickel and ebony were both roughed up at 36 grit and sealed with gflex. As a result, I now pin all of my end caps. It was a good but embarrassing lesson. Now, I cringe when I see photos of thin endcaps with metal. That’s a different thread.
Also, I think African Blackwood or Katalox makes a better ferrule. That is the spot that I think will have more stress, hence more chances of splitting. Gabon ebony is better suited for the body.