Simple syrup is equal parts water and sugar boiled until the sugar has dissolved. So 1 cup sugar, 1 cup water. This will make more than you need for this recipe but you can use the extra in cocktails or iced tea/coffee. I have found that 3/4 cup water to 3/4 cup sugar gets pretty close to 1 cup simple syrup with just a tiny bit extra. 

If you don't have an ice cream maker you can make this in the style of a granita. It will be icier, but still really delicious. Once you make the sorbet mixture, place it in the freezer in a baking dish or other shallow container. Every 30 minutes or so, remove sorbet pan from freezer and use a fork to break up, stir, and smash chunks of sorbet. Smooth and even out sorbet before returning to the freezer. Repeat stirring process until mixture is complete frozen. Make sure to really smash after scraping to get a more creamy, less icy texture.