Not sure where in the world you are, but in the UK I've often used ebuyer and been happy with their service:
https://www.ebuyer.com/store/Storage/cat/Optical-Drives.
I've not used external USB DVD drives, but I've always found that Samsung, Hitachi, LG and Liteon internal drives have been reliable.
Here's a review site's suggestions:
https://www.laptopmag.com/best-picks...nal-dvd-drives - looks like their top pick is a similar Hitachi device to stevef's suggestion.