Homepage Design Help

We are an engineering and manufacturing company that is currently in the process of redesigning our existing site. I have attached some images of the layout of the new site. We ONLY need a homepage designed, nothing else. The homepage should consist of the following: 1) The top part of the page will be product oriented. The attached picture will show that we have 3 sections, "oil management", "thermal management", and "conventional products". We want to have 3 buttons for each of these sections. When one is clicked, it changes the MAIN area above it, that will have a default image when the user first enters the site. For instance, the default page will have an imagine, and have the quote stating: "Engineering, Manufacturing and Assembly Leaders in Thermal and Oil Management Technologies." When the area "oil management" is clicked, that first image and quote will disappear and all info will show up related to the "oil management." WE DO NOT NEED HTML DESIGN, JUST GRAPHIC DESIGN! Please submit your bids, any examples that are SPECIFIC to our site will help greatly in our decision. Please use the blank layout that I have attached for your work, as this is the layout we will be using for the rest of the site.