My money sez it's the callipers. It may not feel like there's much play but they don't need much to clunk like that. Have someone in the car apply the brakes with the car on jacks or stands, grab the wheel and try to turn. You'll see what's what then.
Or stop the car right next to an assistant with good ears. They should be able to tell if the clunk comes from the top of the strut or somewhere lower, like the calliper.
Or stop the car right next to an assistant with good ears. They should be able to tell if the clunk comes from the top of the strut or somewhere lower, like the calliper.