The options you mention will work. A bootable USB drive not only gives you an installer, but has other emergency tools, like Disk Utility, Firmware Password Utility, Terminal, and a Network Utility. Not required, but very handy if you need recovery tools.
If you do a clean install, Migration Assistant does an excellent job of copying applications and user data, so that you don’t have to do individual installs and data copying. Let Migration Assistant do its work overnight.