Customized Wordpress Theme

hi there, i have a wordpress theme that needs to be customized and needs to be more polished for visitors. i want a website that will post technology news on it, like mashable or engadget but i want a design like [login to view URL] which i already have a theme to do that just needs to be customized and polished. The theme is already reponsive theme for mobile platforms, i would like to keep that too. there will be a lot of visitors but they will only comment on the website, thats why i need a very fast interface and programming, there is one more thing needs to be done, the current slider of the website needs to be replaced with a newone like one the [login to view URL] and right next to it, there should be a widget area so that i can place any kind of widget i want right next to slider on the homepage and the top navigation menu should be like on [login to view URL] both in desktop version and mobile version.