You can run whatever your pocketbook allows you. The best would be an X ring, then an O ring, and finally a non O-ring chain. The bike doesn't make enough power that it's a safety issue to run one kind over the other.
O-ring chains are probably the balance between quiet, least maintenance, and longest life for the money.
I plan to use cheap, non o-ring chains though because the bike is designed like farm machinery and intended to be used as such, so that's my take. I use o-ring chains on my bigger street bikes and non o ring chains on my cheaper, older (and smaller) bikes.