We don't think the Expedit bookcase was meant to be mounted on the wall... they didn't have any examples in the IKEA showroom and the sales person wasn't too sure. But we figured with enough brackets ...
Here's what you need: an IKEA BILLY bookcase, a set of drawer slides that could support a wall safe ... a 500-pound capacity ...
Include some wall-mounted floating shelves above, like Ikea's LACK shelves, to create a full wall of storage and seating. To create a banquette or window seat as Farr has done, budget-friendly ...