Is XOOPS good for a hosting site?

The Xhelp module provides a pretty good ticket-based help desk. There is a Zen Cart module that you could perhaps use to sell hosting packages. There's also a mod called Netquery for checking domain details.

Don't know if any of these will do the job. I personally have only ever used Xhelp.

You might want to check the XOOPS hosting forum and see what (if any) modules other hosts are using. Checking your web browser address bar often provides a clue to the module name.

HTH