I have learned to really like cncjs, but I have a higher powered intel NUC running my PC Brains. Not sure it needs it, but it is handy since I can also run Fusion right on that PC to make changes if I notice issues.
But there are many options for the Gcode sender. I am looking at trying Candle which Michael mentioned since it seems really clean and light weight. Also you can try the UI by Openbuilds called Control. That looks to be developed by Peter van der Walt for Openbuilds. Peter originally created laserweb along with others back in the G+ days if I recall. But really any Gcode Sender will do the job. Really once the CNC is running unless you need to Estop, or adjust feedrate it is pretty hands off. Also an MKSTFT has the option of connecting to the MKS DLC with MKSTFT-CNC, so you can even jog to Zero position via the LCD, Set Zero, and Start the code running entirely from the screen no PC required.
I am excited to see how your build progresses. Please do keep the group updated on your progress and ask any question you run into. CNC routers are a whole new animal compared to 3DP. Lots to learn, but being able to produce larger and faster strong parts compared to 3DP really opens up the possibilities of what you can create.