change category layout on opencart design shop

I am making a new webshop using open cart. its a good system but i need a slight redesign of the default system to make the categories horizontal as i intend to have many product. see [login to view URL] / [login to view URL] for example of a horizontal products menue instead of categories on vertical panel i want them on top with drop down menu, see ebuyer for exactly the look. i also want to be able to add some banners. the coder needs to be commited and looking for long term relationship and he/she will be called upon for future work from time to time.