As I would like to carry the authenticator around I wanted to make it have the same formfactor as a USB flash drive. On aliexpress I found some small screens that looked like they would fit my description:

* SSD1351

* SEPS525

* 80x160 ST7735

* 135x240 ST7789

* 40x160 GC9D01

* 172x320 ST7789

When I received the displays, I dropped some of them straight away. The SEPS525 and SSD1351 were to wide for my application and the 80x160 ST7735 and 40x160 GC9D01 were too small for my liking.

This left me with the 172x320 ST7789 and 240x135 ST7789. In the end I decided on the 240x135 ST7789. This screen is slightly larger than a USB A port, has quite a high resolution and pinout matched the previous screen I was using (the 80x160 ST7735).