Preston is alright, at least all the trains have to pass through the station
It's almost the same as Carlisle in terms of freight, however you will lose the Frieghtliner coals (which use the Settle line)
As for parking, if it is for several hours then there is plenty of on-street parking within reasonable walking distance (Cliff Street area), although it can appear full between 08:30 and 11:00 on weekdays