SanDisk Ultra 3D 2TB SSD
For secondary storage in my new build, I chose the SanDisk Ultra 3D 2TB SSD, bought on Amazon for US$209.99. Being SATA III rather than NVMe, it's slower than my addlink S70, reading 560MB/s and writing 530MB/s.
SATA
SATA storage and adapters, from a 2TB SSD to USB-C and USB 3.0 bridges.
Cable Matters USB-C to SATA 2.5″ Cable
The Cable Matters USB-C to SATA III 2.5-inch Cable retails for US$11.99 on Amazon. This 25cm cable connects 2.5-inch SATA hard drives to your computer over USB-C, supporting USB 3.1 Gen 1 speeds to 5Gbps.
Vantec NexStar SATA/IDE to USB 3.0 Adapter
I bought the Vantec NexStar SATA/IDE to USB 3.0 Adapter from Challenger for S$59.90, or S$53.91 with member's price. As the name suggests, it converts an internal SATA or PATA drive to USB 3.0 for plug-and-play access.