Even though I loved the hell out of Linguistics, it would probably be more convenient to do as a breadth.
Judging by what I've heard from friends, some of the psych units aren't very well taught (I believe one of the assessment pieces is to write an essay about how a sunset makes you feel...) That said, I know it gets 'meatier' in later years, so maybe someone else can offer insight there.
Honestly, once you've got a BA or BSc you can go on and do your specific post grad studies in whatever area, though I'd imaging it's easier to go from Science to Arts than the other way around.
Science with a Linguistics breadth would be my recommendation, but it depends on whether you're more interested in the biological/ neurological side of things or the social/ technical language based stuff
