I recommend firm, ripe Freestone peaches (or nectarines) for this recipe versus the Clingstone. Freestone peaches are exactly what the word describes: peaches that will release their grip from the pit cuddled inside. Since the pits remain in the peaches as they bake, your guests will have to remove the pits themselves. Better to have relaxed peaches than ones your guests fight with to release the peach flesh.
* Eyeballing my peaches at the market, I thought they were "medium" sized. Apparently in California, our medium peaches are actually monster-sized peaches. Because of the snug fit into the 9-inch pie plate, I trimmed my peaches slightly so they'd fit. If your peaches are large, the crust will still blanket them nicely. Try to have a little space between each peach in the dish, so you can sling the crust in between the peach cleavage a bit, to form the boobs, I mean, bowls around the peaches.
** If you prepare this well before dessert-time and peaches have cooled considerably, there will be some peach shrinkage away from the biscuit.