Is that 200 total or 200 per part? How many parts? Where's your buying preference?
Cpu mentioned would be worth getting. Bios needs to be on v3.40 first before updating to later bios versions supporting Gen3. Explains what to do on the motherboard support page > Bios.
Since you only have two dimm slots, i'd go for 2x 16GB. 16 total is ok but going forward into the next few years 32 is going to be worth it. There isn't a QVL listing ram for Matisse (3rd gen cpus), only for Pinnacle (2nd gen 2600 etc) and Summit (Your cpu gen). I'd say Gskill CL16 anywhere between 3000~3600 should be fine.
Agree on changing PSU.
Another bigger SSD, 2TB either 2.5" Sata or Nvme. The usual 2.5" Sata for games would be fine as differences between Sata and Nvme concerning IO speeds isn't that much. Gaming on SSDs is far better than mechanical, not just for loading levels but assets loading on the fly. Gives a smoother experience. Editing and stuff would favor higher throughput from Nvme i guess? I'm not sure on that.
If you do get an Nvme SSD, i recommend looking at your manual which Sata connectors can be used and when. Because inserting an M2 Sata or Nvme can knock out a couple of normal Sata ports to allocate bandwidth. Some mobo's allow Sata port functionality if M2 SSD is Nvme (PCIe SSD) and not Sata. M2 Sata is different to 2.5" SSD. M2 is the form factor, the SSD's using this connector look like memory sticks, there are Sata and Nvme versions.