For most of these models, nowadays you will want both the 180w and 230 power supply. These are essentially power supplies that are usually used on laptops, so they have power bricks that sit outside of your PC. What you are showing in that picture includes an ASUS OEM holder for both supplies. I'm not sure what it's called, but I haven't been able to find one online. You might be able to find one every once in a while if you figure out what the call it.
Double check the models/compatibilities, but these should work if you have G20AJ:
230w:
https://www.sears.com/asus-731-154937000130444-230w-power-supply-charger-for/p-A101949390?sid=ISxMP3...180w:
https://www.amazon.com/ASUS-180W-Notebook-Power-Adapter/dp/B00HWI6ZY8These are ASUS brand. You could probably find cheaper if you go off-brand.
By the way, with the 2 power supplies, you can upgrade the GPU pretty well (with the proper "blower" style fan). I have a 1660 running in mine now. I've read of people doing GTX 2000s and beyond. Some people have also successfully used a 330w power supply.