Wordpress into promotional site

We have a wordpress website that we want to add all the promotional products and clothing products etc etc (like having different ecommerce sites without the cart and with quoting system) too but with keeping the site look the same. The add-on needs to work seamlessly with wordpress and be 100% seo friendly. Here is a couple of sites we are looking to achive from ours [login to view URL] [login to view URL] 1 key part of this project is to have a per product quoting system so a customer goes on to a product page and types in Full Name Company Name Quantity No. of colours Email Address Telephone Number and an email is sent directly to us for the enquiry and what product they are looking at. All the different products will be put in by ourselfs but will need a catagory system with grid and list view that the customer can change like an ecommerce site but with a quoting system instead of a shopping cart. A side menu of all the promotional catagorys and sub-catagorys that just for that catagory (eg different side menu for the different parts of the site promotional item, clothng, signs eg) will need adding which is automatic so when a catagory is added in admin it automaticly adds to the side menu. This addon will be needed for promotional items, clothing items and possibly signs so need to be something that we can just add to and expand as and when we need. We would also like to have a css colour change themes that the customer can change with a click adding to the website header bar you'll see from the website where and what colours we want. Please PM for the website address. key features to this project 1. easy product listings with catergory management and side menu of catagories and sub-catagories 2. product page quoting system like other promotional websites (listed above) 3. system to be easy to use and expandable to the other catagories of the site 4. customer adjustable themes (css, java) 5. 100% seo friendly