If you want a more unique name, you might as well make one yourself. As long as it conforms to the rules of English pronunciation, it will be OK. I have named someone Asea before, and the girl is named after Sea. This word comes from...
If I can help you think about it...
zion: This word is not an English name in the exact sense, it is a word, which means "heaven" pronounced [ 'zai?n ]（Zai En）
It's hard to find English words with similar pronunciation to your name. I searched for a long time and couldn't find any... Zihao's pronunciation is very difficult to find. I think Zion is a great name...I’ve been looking for it for a long time~