Yes, you can buy the premium themes that show up in your dashboard, but you cannot install themes you find out and around on the internet.
The site you referenced is NOT A WORDPRESS.COM SITE and is not even using WordPress at all. From the looks of it it is a custom built site.
You need to look through the themes at http://theme.wordpress.com/ and find a theme that will work for you and has the basic features and layout you want. If you cannot, then you will need to self-host a WordPress.ORG installation on third-party hosting service such as go daddy, dreamhost, blue host, etc. Then you can start a search for a theme somewhere on the internet that will work for you. You may find one, and you may not. If you do not, you can have a custom theme built for you and the cost for that could be anywhere from $500 to $5000 depending on your needs and how much time it takes them to design it for you.
The Pro Bundle gives you just what it says on the Pro Bundle support page. Nothing more.