Most folks visiting Memphis put together their own trip. Perhaps someone will chime in with info on that site.
If you won't have a car, I suggest you stay downtown if possible, where you can walk or take the trolley to many attractions, restaurants, etc. There is a free shuttle from downtown to Graceland to Sun, but you must take the studio tour to use it,
You could stay at the Days Inn or Heartbreak Hotel near Graceland, but remember that there aren't any other tourist attractions in that area and dining options are limited. HH does offer a shuttle to downtown for its guest for a nominal fee.
I don't know what kind of ticket package you're seeing on that site, but below are links for discounts on Graceland and Sun. For the Sun coupon, click on the "deals" on the page.
http://www.elvis.com/coupon/default.aspx
http://www.memphistravel.com/sun-studio