Install standalone instance on cluster server with SQL Server
It is a hell of a bad idea, but it might work. I have done something similar in the past because it was the only possible solution and I can confirm that it works. 

The only thing to be careful about is the versions: you will probably get warnings about installing sql server 2008 on Windows 2016. Also, keep in mind that it's not supported (which doesn't mean it won't work).

However, this is something I would never do in production: do yourself a favour and find a different machine for that SQL Server 2008 standalone instance: at least, you won't get shared features incompatibilities and the like.