In a small saucepan, combine diced peaches and sugar. Bring to a simmer over medium heat and cook for 15 minutes until thickened - set aside to cool completely. In a large bowl, whisk yogurts and transfer to an ice cream maker. Mix according to the manufacturer's suggestions, until thick and frosty (about 10-12 minutes). Add peach mixture to the machine and continue to churn for an additional 5-10 minutes, until thick. Enjoy immediately, or for more a scoopable yogurt, transfer to a freezer-safe container and allow to harden in the freezer for one hour. Store in the freezer for up to one week.