Place chopped peaches into a saucepan. Add water and a can of peach nectar. Cook over medium heat until soft and cooked through, about 10 minutes. Remove from heat and drain peach juice. Place peaches into a large bowl; add sugar and allow to cool to room temperature.
Add sour cream, heavy cream, vanilla extract and lemon juice to the bowl with the peach mixture. Using an emersion blender mix together to incorporate. (If you do not have an emersion blender, a food processor works just as well.) Remove ice cream insert from the freezer and turn the machine on. Pour the peach mixture into the insert and follow manufacturer's instructions for churning. Freeze ice cream in a covered container until ready to serve.
Serve warm Praline Pecan Sauce over ice cream.
In a large saucepan over medium heat, combine all ingredients and bring to a boil. Reduce heat, and simmer for 10 minutes, stirring frequently until smooth and syrupy. Serve warm. Store leftover sauce, covered, in the refrigerator.
A few hours before making, place ice cream insert into the freezer.