Can't locate unsweetened coconut flakes... will scones be too sweet if I use sweetened?

you could always reduce the sugar in the recipe, or increase the amount of salt if you're worried. but 1/4 cup brown sugar isn't a lot so it shouldn't be too troublesome...

The scones are not very sweet to begin with, so I believe it will be ok to use sweetened flakes

Have you tried looking in a health food store for unsweetened flakes? They really would be better,