ISPConfig i think that this is the most balanced free hosting panel nowdays. it is secure, because you install manually and you secure manually all elements and because the panel itself is secure and stable enough...
if you want a very easy and quick hosting panel for your server, maybe ISPconfig is not your case. it does not have a one-click installation script, but need work to prepare it. the prize is that when you complete installation and tuning, your life will be easier if you want an advanced panel to use