Bare drive means just the drive - no cables, screws, software, or anything else.
OEM means as supplied to system builders to build into systems. May range from a bare drive up to a fairly complete package of bits, but rarely a pretty box.
I've always found LG drives to be sound and very relaible.
Using any make of DVD disks though is a bit like wishing for the moon - no-one will ever have tested it with all makes, so no-one will or can give you such a guarantee. However well know branded makes of drive will normally be quite happy with well-knon branded makes of disks.