PS Audio Ultimate Outlet/P300 power cord ?

I am in the midst of getting the PS Audio Ultimate Outlet and the P300 power regenerator. I was wondering what combination of power cords would be best to use with these units. I am using power cords from a few different companies and was wondering if I should be putting the "better" power cord between the Ultimate Outlet/P300 and the power receptacle, or if I should be using the "better" power cord between the UO/P300 and the component (cd, preamp, dvd player). I would like to hear from other PS audio owners to see which combination works best. Where does the power cord make the biggest difference?

Thanks!