Use 2 separate 24 or 30'' vanities instead.

I like vanities that don't go wall to wall. Even though this one is in an alcove, we didn't go wall to wall. (Two separate vanities would also look nice, but definitely 30" - no reason to go as small as 24" since you have 7' in total)

The free-standing furniture look is my preference too, but is 6" enough space on each side? I mean for cleaning access?

Thanks! I'm not sure if 6 inches is enough space on each side for cleaning access. How much space do you have on each side?