Audio cable is irrelevant, as modern drives do not use them. Audio for CD's is provided by digital extraction (realtime ripping) and DVD audio is decoded by the DVD playing program, not the drive itself.
I assume you know for a fact that your machine can use SATA drives - if you computer is not recent, it may not be able to. You need to be sure of this before buying anything.
Both of those drives are OEM, so they will have no accessories at all. This is normal.
Cases usually come with extra screws, and motherboards with extra cables, but if you didn't build your computer you may not have these. I have seen some prebuilt machine cases which have extra screws mounted inside them, so you might check yours if you haven't yet. In fact, your case may have spring clips instead of screws, in which case you would not need screws at all.