1. The devs did not announce yet which algorithm will be used for mining after Atlantis, so we do not know if GPU mining will be possible (or profitable) on Dero. Maybe it will be not Cryptonight-family at all, or only CPU mining with daemon will be possible.
2. For mining rig 4Gb ram and 64Gb SSD is enough. You don't need hdd 500gb at all.
3. Power supply unit 600w will be enough only for ~2 video cards AMD and for ~3 NVidia. You should sum energy consumption for all your video cards and add ~100-150 W for the processor and other stuff.
4. Note, that AMD Ryzen 7 1700 processor gives ~520 H/s with overclocking on CryptoNight-V7, the same as Nvidia GTX 1060 - 6 Gb. But it gives only ~200 H/s on CryptoNight-Heavy (GTX 1060 gives ~420 H/s on heavy).  I5 3570 processor has only 6Mb L3 cash memory, so on CryptoNight-V7 you can use 3 threads with ~70*3=210 h/s and only 1 thread on CryptoNight-Heavy with ~70h/s, as it requires 4Mb L3 cash per thread.
5. AMD Ryzen 7 1700 is more energy effective with the same hashrate than Ryzen 7 1700x or Ryzen 7 1800. For Ryzen I suggest to buy a good cooler, as the cheap one will be noisy on full load. AMD processors are hotter than Intel.
6. RX560 4Gb is not good either, as it gives only ~310 H/s. The benchmarks for CryptoNight-V7 you can find here: https://docs.google.com/spreadsheets/d/18IrFEhWP89oG_BTUsQGS5IDG8LUYjCHDiRQkOuQ4a9A/edit#gid=1518673099