Add eCommerce and login functionality -- 2

Hello, I am looking for somebody to add eCommerce and login functionality to my pre-existing website. The current website can be found at [login to view URL] 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 paypal and stripe. Lastly, I would like to have a permanent login/ logout/ sign up box with social login in a similar place to where the shopping cart is. There is some empty space bellow the menu tabs that I would like to be used. If possible I would only like the shopping cart to be present on the home page when there are items in 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.