Crisp and beautiful web design

We are a software startup looking for a first-class web designer to build our site including basic graphics and a logo. We are building an online application that will live within the site....the web designer will work with the front-end designer to ensure that the design plays nicely with our core functionality. We are looking for an individual that has experience doing smaller projects that are clean and well-executed. We have already created wireframes for the site but need a strong visual sensibility. We are aiming to have our prototype completed within the month and thus are looking for a public facing website in the same timeframe.....this will not be open to the public but rather will be used to show trial customers and potential investors. That said, it must still look crisp and professional. Bonus points for designers that have worked work on sites that use RichFaces in the past.