If you can - buy new! Not upgrade!
SSD Samsung (NVMe PCIe 4.0 M.2 if possible) or other brand you like (check also best SSD in 2020)
Samsung 980 PRO (PCIe 4.0 NVMe) 500Gb or 1Tb (in case RAID 0)
Samsung 860 EVO (2.5 Inch SATA III) - long life/warranty
Samsung 870 QVO (2.5 Inch SATA III) - cheaper cost
Memory from 16 Gb (4 or 2 channels)
Windows 10 or Linux Ubuntu 21.04 (or your choise)
AMD TRX
SSD MVMe M.2 512Gb or 1Tb minimum (PCIe 4.0 if possible and not SATA) around 7000 mb/s
RAM 16Gb+
Intel CPU or AMD Threadripper (Ryzen 5000 series for home)
SSD MVMe M.2 512Gb or 1Tb minimum (PCIe 4.0 if possible and not SATA) around 7000 mb/s
RAM 16Gb+
Motherboard X570 or new
Asus on Intel or AMD Ryzen 5000 series
Select your device on the comparison site