It's odd that the Airport Extreme route didn't work. By all means it should have; it simply creates a network share from the disk.
Anyhow, if you go with the Cinema Display, it should work. But only the Mac plugged into the display (and by extension, the HDD) will be able to see the files on that disk.
Team Anandtech: Assimilating a computer near you!
GameStop - An upscale specialized pawnshop that happens to sell new games on the side
Todd the Wraith: On Fruit Bowls - I hope they prove [to be] as delicious as the farmers who grew them