Those both sound plausible. I think in my mind it really depends on what type of source analysis method you're doing... If it's BEM, then hopefully we can get the direct to surface part working. But the NIFTI export is a good fallback if necessary.
I'll confess, I'm an MNE user and haven't done much with BrainStorm, so it'll be an adventure. Upload link sent to you by email.