It depends on what your intent is with the new drive. The provided links bring you on the right track. However, if you also want to burn BD-50 discs be warned. The LG drives only burn all discs up to BD-25 in good quality. But make trouble with BD-50.
So - for reading go for the LG type drives. If burning is the priority I suggest Pioneer BDR-209 or BDR-212 also for BD-50. The trade-off: The Pioneer drives can't be modified (yet) to read UHD discs.
If burning BD-50 is something you are interested in, see this thread in German and run it through Google translator. If not, just ignore it.
https://forum.redfox.bz/threads/uhd-filme-backup-auf-bd50-discs.77673/#post-508611
FYI: I have 2 LG BH16NS55 flashed to ASUS 3.10 firmware for reading and a Pioneer BDR-209 for burning.