Depends
If you incounter lite winds alot, go for the 150%. If the winds are usually 10K or so, go for the 130%. If you have winds under 5K most of the time, then I would get a drifter. These are made of very lite material. They don't go to windward as well as a genny, but do much better down wind, and are great on a beam reach in lite air. The asymetrical spinnakers are grate down wind in lite air, and after you get used to using it, you may find your self flying it on a broad reach in winds up to 15K. Don't forget a storm jib for those days with winds over 25K. You would be surprized at how well these small jibs work, and how much they help you controll your boat. You will be enjoying a good sail while others are dropping their sails and motorring in.