I need a redesign for a web app under development.

Description

We are developing an app to help with the cataloging, curation, collation, navigation and administration of multiple dashboarding (business intelligence) systems.
I will provide you with what the site looks like now and I need a few design concepts which we can select three. I will then need you to code that into the site css.
The site is only four parts, which are- a left hand navigation which collapses into icons- a top navigation in the content page which currently consists of only 4 icons- a control panel to view statistics and functionality on dashboard administration- a content page where administrators can add their own content for users to see
I will provide a working version of the site, and a cleaned up branch of the underlying code. I would like to see several design concepts which should be professional, clean, simple - designed to be viewed by corporate professionals. We can then finalise two or three designs and then you can update the code so I can merge it into the master copy.
If you could provide a portfolio of appropriate previous designs during the bidding process that would be helpful.
Please note that I will ONLY contract / pay through peopleperhour.