How do I run multiple Minecraft server instances on a single physical server?
Solution 1:
Yes, that should be enough. Also make sure they're running in different folders so they don't try to overwrite each others' files. If you're using plugins with SQL databases, make sure they use different databases. Basically just keep everything separate.
If you don't want the clients to have to type in the port number, you can use a SRV record to give your server a different hostname. (e.g. creative.your-server-name.com)