SQL Server - Which one do I need

Hello All,

I have install Visual Studio Professional 2012.  I will develop a application that will use SQL Tables on the PC only, NOT on the web.

Questions:

(1)  What SQL Server should I down purchase/down load/Install?

(2)  When I implement the application on another PC will the other PC have to have SQL Server installed on it  or will my application have everything it need?

(3)  What LINK do I used to purchase the SQL Server from question 1 above?

Ed.

ecb