Here is a good video by Simon Gawesworth of RIO on how to choose the ideal Spey line for your application. It covers the 2013 range of Spey lines by RIO and is very informative on the purpose and usage each of the Spey line type from Skagit to Scandi to traditional long belly Spey.
Most of RIO Spey lines do not come integrated with shooting / running line. You will have to buy a separate shooting line to loop to loop to your Skagit or Scandi head. Below is another video that covers the 2013 range of shooting lines by RIO to help you select the ideal shooting line for your application.
For those who like to read about buying the right line for their Spey/Switch rod, here is a good article by American Fly Fishing Co.
For those who are still not sure on whether to choose Skagit or Scandi heads, here is an article by Whitney Gould on Skagit vs Scandi heads.
The more recent RIO Spey line that caught my attention is the RIO Scandi body. The profile of this line is very similar to my favorite Wulff Ambush line but it comes in the form of head only in 3 densities, floating, intermediate sink and 5ips sink rate. This line is very versatile because it can cast both Scandi and Skagit style equally well as long as you match it up with the appropriate Spey versileader.