Adding to what Chris said, after you install PowerServer on a remote machine you will need to enable the FTP option of IIS on that remote server and configure your server profile in PowerBuilder to FTP your project to that remote server with the FTP credentials. The FTP's home directory needs to be the same folder as your HTTP's home directory (usually c:\inetpub\wwwroot). It would be very good idea to read through the product manuals because a remote config is more involved than a local config.
No problem to install the PowerServer piece on a separate machine. Just run the PB 2017 installation and uncheck all the product pieces except PowerServer. Then proceed to complete the installation. Just make sure that the machine you are installing PS on is accessible firewall wise from your development PC and that should do it!