I can't help you with ice cream. But Mario Batali has a recipe for Lemon Sorbetto in his Molto Gusto that might be suitable:
10-12 lemons, preferably organic
1/2 cup sugar
2 cups simple syrup
Zest 4 of the lemons, using a Microplne or other rasp grater. Put the sugar in a small bowl and, using the palms of your hands, rub the zest into the sugar.
Juice enough of the lemons to make 2 cups, and transfer to a medium bowl. Add the simple syrup and sugared zest and whisk well to combine. Do the egg test and add more juice or water or more sugar syrup, a little at a time, if necessary. Cover and refrigerate for about 3 hours, or until thoroughly chilled, stirring occasionally to dissolve all the sugar.
Strain the lemon juice mixture through a fine-mesh strainer into a bowl. Freeze in an ice cream maker according to the manufactere's instructions. Pack into a freezer container and freeze for at least 1 hour before serving. (the sorbet is best served the day it is made).