I myself, agree with Jojo on most of his opinions.
Rio's Speylines are some of the finest made with the best tapers to be found plus the Slickshooter Process produces a super slick line that shoots like a rocket when needed.
I would shy away from the Windcutter unless you are fishing a super short rod, especially if you are a novice. It may be easy to learn how to cast on the Windcutter but learning on the Windcutter will allow you to devolp bad habits that will be magnified when you try to toss a longer belly Spey line.
Learn on the Midspey and jump down to the Windcutter if you decide you prefer a shorter head.
I have listed a link to Simon Gawesworth's line reccomendations for all the popular Spey rods out there...
Rio Line Reccomendations