What stores sell pastry or tart shells?

You should be able to get them at the supermarket.

You could by pastry sheets, and cut them to suit your pan.

White Chocolate Berry Pie INGREDIENTS: 1 pk (15oz) Pillsbury refrigerated Pie crusts 5 Squares BAKER'S Premium White Chocolate 2 tb Milk 4 oz Philly brand cream cheese [softened] 1/2 c Powdered sugar 1 ts Orange peel [grated] 1 c Whipping cream [whipped] 2 c Raspberries or sliced Strawberries or both mixed DIRECTIONS: 1) Prepare and bake the pie crust according to package instructions for one crust baked shell, and let cool completely... 2) Microwave 4 squares of the white chocolate and milk for about 2 min. or `til almost melted. Stir `til melted and let cool to room temp... 3) Beat cream cheese, powdered sugar, and orange peel in a small bowl with an elec. mixer on low speed `til smooth. then fold in the white chocolate mixture... 4) Fold the whipped cream into the chocolate mixture and spread into the cooled pie shell. Arrange the berries on the filling and drizzle the remaining melted chocolate... Refrigerate for at least one hour before serving...

Tenderflakes makes them and you can buy those in the cooler section where the frozen pies are they have 3 sizes, mini,small and large then there is the deep dish .

http://www.tenderflake.ca/Images/products/miniTART...