4. Retains the original CD inlay cards, though not necessarily the jewel case as well.
I would suggest you reconsider this last point. Jewel cases are by far the best way to store the disc. The design means you lift it out of the holder by holding the edges. Removing and replacing CDs in soft cases creates friction against the disc and reduces its playback life. It sounds anal but its true.
I would look at some simple shelving. 700 CDs sounds like a lot but can easily fit on one long shelf or two smaller ones. The advantage being you can see the spine of each disc and should you need to add/remove a disc, its a simple matter of adjusting the stops at the end.
I'm All Ears.