I have 3 of them and really like them. I have no need for over 60+ Hz at the moment and these have been great for me looking to get larger real estate and clearer, cleaner screens.
LG 27UL850-W (or nearly identical and cheaper LG 27UK850-W) is probably your best bet. At 400 nits (DisplayHDR 400 certified), it's a tad below your 500 nits requirement, but it has many other things that make it ideal for 2017 MacBook.
USB-C that can charge your MacBook
2 USB-A ports
Built-in speakers
Great color accuracy, especially after you calibrate it