Hold your horses, I’ve found a cool seed!
That’s not just a bad pun. You can literally hold your horses in this seed because you will spawn on a small island with only horses!
There’s also a sunken shipwreck very close to the island at XYZ: 276 34 13. The chests in the ship contain a Leather Cap, Compass & Buried Treasure Map. Perfect for a pirate adventure!
Tested in Minecraft 1.13.2 (Java Edition).