the market has thinned a bit, so you gotta google, ebay amazon your way through the remaining sellers that have them, e.g. some really old ones https://amzn.to/3rnCcZH
ebay may have a few more options.
My suggestion> there are some really expensive ones that can be ordered region free, like from Oppo etc, but it might be better to just get a cheap one for the odd US disc you have and have you primary player be of better quality/newer.
Another popular choice is buying a second-hand PS3 and jailbreaking it to allow for multi-region capabilities. (I’ve done this but it has a downside of the annoying;y loud PS3 fans making a lot of noise while playing discs)
I don’t think you can go wrong with either company @makesthemovie suggested. I personally deal with 220 Electronics but have heard a lot of good things about Bombay Electronics.
Amazon.co.uk. has lots of these. Mainly Panasonic brand. When I got mine in 2018 it was £58. Now they’re £158.
Sample model: Panasonic DMP-BDT167EB-K Smart 3D ICOS Multi Region All Zone Code Free Blu-ray Player. Blu-ray zones A, B and C, DVD regions 1-8. YouTube, Netflix etc. HDMI output. HDD Playback.
Make sure it’s region free Blu-Ray, because some companies say region free, but its only the DVD part that is region free