The rest of the world use family name first, then name, like Yao Ming. So... his nic is actually. Mo D.
A nickname needs to be short. I don't like Donuts, because it sounds soft as hell. I like D-Mo or DMo ok, because it's short. Good for tweeting. If you don't like the sound of it I suggest you go with Donatas. It's a unique (NBA) name. No need for a nickname.