currently the only way you are going to have a turbo P-5 is to either ONE, have a custom turbo installed...OR TWO, wait till mazda offeres the mazdaspeed turbo set up as a kit...which I DO hear is in the works.
i've already started to save the pennies for the mazdaspeed turbo...even if they don't technically release one for the P5...i'm sure you could get your hands on a unit from the mazdaspeed protege
believe this please...if the money is in mazda's face, they will have no problems selling the turbo as a kit, why miss out on that much potencial money off of previous year's cars???