Thanks everyone for the fast replies!
For the motherboard I had a look for what is available here and I have found a kit (comes out much cheaper than buying RAM, CPU and Mobo separately):
AMD RYZEN 5 3600 B450 Tomahawk 16GB RGB Upgrade Kit (for 7,499 ZAR - 500 less than the X470)
MSI B450 Tomahawk Ryzen Motherboard
AMD RYZEN 5 3600 35MB Cache Up to 4.2GHz CPU
Corsair Vengeance RGB PRO 16GB (2x 8GB) 3200MHz
Otherwise I'm looking at something like the following: (which works out more expensive at 7,647 ZAR)
Ryzen 5 3600 (3,799 ZAR)
G.Skill TridentZ RGB 16GB (2x8GB) DDR4-3200MHz CL16 (1,849 ZAR)
Gigabyte B450 AORUS ELITE AMD B450 (1,999 ZAR)
For the GPU I have looked at the RX5700 and RX5700XT and the following comes up:
From XFX there is a 5700XT with stock cooler design (blower) for 7,099 ZAR and the THICC variant for 7,599 ZAR.
Other than these options there are just RX5700s from Saphire and XFX for under 8,000ZAR. If I go above this price more options are available As seen here
For the PSU:
Preferably I would replace this as I don't think it is the most stable thing in the world anymore.
Finally, the SSD:
I can replace the Samsung drive with the Western Digital WD Black SN750 250GB M.2 maybe? This comes out to 1,365 ZAR
Let me know if I should make any of these changes? I don't know if only gaining 500ZAR on the Mobo/CPU/RAM is that much of a win, but as you indicate the X470 platform may not be necessary. Thanks again for all your suggestions!