Add eCommerce and login functionality

Hello, I am looking for somebody to add eCommerce and login functionality to my pre-existing website. The current website can be found at www.roarsport.net. As you will be able to see, I have attempted to do this myself using the drupal commerce module. However the themes do not match and the layout needs smoothing. The website will need to have a permanent shopping cart/ checkout on every page that doesn't affect the video module on the home page. You don't have to use drupal commerce, however the payment gateway must be compatible with Worldpay. Lastly, I would like to have, like the shopping cart, a permanent login/ logout/ sign up box with social login. As you will see, this has been attempted but I am struggling to position it. I'm sure this is quite an easy job for somebody with the right know how. I am very open to suggestions on how best to achieve this, but preferably, I would like to use up some of the white space in the top right of the website. Full admin and ftp can be given and if required, access to our VPS.