Choosing which wing to buy should be based on an honest appraisal of your flying and your potential annual expectation, how much time will i put aside, just weekends and an occasional holiday, bunking off work early and flying in the evenings etc. In short don't plan to run before you can walk, take your time to learn the sport well and it will be as safe as houses and not offer too many frustrating or frightening moments.
I found a great article published by the BHPA which echoes what we've written in how to choose a paraglider safety and security are worth so much more than potential pre conceived gains in performance over ability. Have a read and if your unsure drop us a line and we'll advise accordingly. Typically it will be your instructor at the end of a course who will advise you as to what would be most suitable.