I found some clearance drawer pulls at Meijer to use as tie down points if I want to have a duffel on top of the case. I used some neoprene plumbing washer to keep it watertight.
I stopped at the local Chinese Import Shop (dollar tree) and found a couple little pencil bags that would be good to bolt to the top of the case. I just used the same holes as the drawer pulls use. Oh, and I got one of those little led stick on lights. Who knows how long that will stay there, but we'll see. :)
I am pretty happy with the setup. It's very utilitarian (ugly) to some, but to me, I enjoy the look. Plus, I just need to loosen 4 nuts and its off the bike completely with no trace of it ever being on it.