* "Wiliama" is the most common way to transliterate "William" in Hawaiian. It's a straightforward phonetic adaptation of the English name.
* "Keola" means "strong, healthy, vigorous" and might be a good choice if you are looking for a name with similar connotations to William.
Ultimately, the best way to choose a Hawaiian name for William depends on your preference and the meaning you want to convey.