Large Display Tank Suggestions???

We are getting the company display tank sorted out, the basic tank dimensions will be a little larger than we originally planed but Im not complaining. Dimensions are 18'x7'x8'. What Im trying to figure out is what can we do to make it funky? Should it just be its huge self and have a 14'x5' front window and a 4'-5' vertical oval on one side? What do you think of it having a step up on a far end that you can crawl under that you can put your head in and look around inside the tank with a vintage dive helmet? I want it to have a large free swimming area, but can anyone think of some feature to add that wont take a ton of swimming space away? If it was bigger I would do an acrylic tunnel. I need the swimming space for mini hammerhead sharks, it will have reef fish as well. what would you do?
Any ideas? Thanks....
"Im smiling, and scratching my head at the same time"