I don't know much about Winsor Pilates as it just tends to be localised to America - it's not very well known in the UK or Australia (where I live now). I have, however, read the Winsor Pilates book - all Pilates styles are different but the principles remain virtually the same, I have found. One book I was very impressed with was "The Pilates Body" by Brooke Siler. She is American and she owns a studio in NY City - she trains a lot of stars! I have found her technique very similar to Michael King (who I trained through) and her book is very easy to follow and provides the reader with all the necessary background and principles. Definitely worth a read!
Certified Pilates Instructor (Pilates Institute UK)