This is undoubtedly a simple question for the right person.

I've got a 9x7LX with the second internal drive bay empty. I'd like to fill
it up with something, but at this point my head is spinning as to possible
choices. Will an ST19171N slip right in? Is there anything else I need to
buy? Is there some place I can go to determine exactly what will work in
this internal drive bay? It appears that suitable drives can be had rather
inexpensively if you know exactly what you need.