Sell the ram and buy some cheap used ddr4, 16g preferably with 3000 speed. You're definitely gonna need a new mb, cpu, and gpu. If you want to go the intel way, get a 1070, assuming your monitors aren't g-sync and are only 1080p 144hz. An i5-7600k should pair fine with that, and for the motherboard, get a z270 asus prime one, as that will do the job fine.
If you're going the AMD Ryzen way which I recommend, get the R5 1600, as the 1500x only has 4 cores 8 threads i think, while the 1600 has 6 cores 12 threads and is $20 more expensive. Get a cheap B350 Msi pc or tomahawk, all the same. For the gpu, 1070 should be good with that as well. You won't need to get a new power supply as the new gpu's and cpu's are more power efficient. That's pretty much it.