This logo will be imprinted on black the awning over our new office (see awning.jpg and front.jpg), so it absolutely must work against a black background.
The logo itself should be simple and memorable. Ideally there will be a single image in the logo that captures the essence of the brand and can be used in place of the full company name when needed (think of the Apple logo or the Nike swoosh which instantly identify the company without requiring the name to be written out).
Also note that we routinely deal with financial institutions, so the logo must be somewhat classy and professional.
In addition to being on the awning in front of the building, we are going to be rendering the logo in 3d and projecting a spinning image of the logo in our lobby to attract attention from foot traffic, just something to keep in mind while you work on your design. The logo should be cool if you think of it as a projected 3d hologram, as in the hologram.jpg attachment.
As a bonus, if you send us your contact info we'll be more than happy to send you nice photos/video of your logo on the awning and as a 3D rotating hologram. It will definitely be a cool differentiator for your portfolio.
And then of course our logo will be used on our Web site and business cards.