I run a GS2 and control it over modbus. You could control it over modbus or the digital inputs if you want mach to control it. You can operate it from the front panel if manual operation suites you. List your requirements and I'm sure you will get some suggestions on how to do it. My suggestion is to do it over modbus. This will have very little to do with your screen. Watch the video tutorials on modbus and download the manual for the drive. All the addressing and parameters information is in the manual. You can get Qmodbus for free. Its a nice app I use to help answer modbus questions. Get the drive, wire it up to your spindle, use qmodbus to turn it on/off/fwd/rev and adjust the freq. Once you get the hang of it will be pretty easy to set Mach up to control it.
Brett