As this is more akin to a gallery show than a museum exhibit, you should include a small placard (4x6 mounted on foamcore) with each print indicating prices, along with the other usual data: title, your name, date, medium, size, etc. Also, be sure to leave either business cards or small take-aways for bank customers so that they can contact you and become YOUR customers, as well. If the bank does not want prices listed on the walls, and some business do not (museums almost never allow that), you can ask to leave a price sheet at the reception/managers desk. In addition to the placards accompanying each print, you should think about a larger placard in the 18x24 inch range that has your name, bio, and a short artist statement. That will give viewers a base for understanding your work as well as your motivations.
If you can get the bank management to agree, have an official exhibit opening after the bank officially closes. Wine and cheese are sure to bring in people. If that is not an option, an informal lunch reception may work. Either way, try to have a specific and official opening day designated so that the local media, whether TV, radio, newspaper, etc, have "hook", which is slang used in the media for a justification for covering an event. Mondays are great days to get local media folks to cover a story, as it's usually a fairly slow day and they are often in need of short story ideas.
As for image placement, depending on space available, you might be somewhat hindered, but be as deliberate as possible. Try and group prints using whatever criteria you deem works best. People don't respond as well to simple randomness as they do to a sense of order, whatever that might be: subject matter, feeling, location, mood, etc. It will all depend on the specific photos and, of course, you.
Shows can be a bit stressful, but try and have as much fun with it as possible.