What suffix of location is more natural in Standard Mandarin : 头, 面 or 边?
There are regional and personal differences.
I personally usually use 边. (BTW I am a native.)
面 is also OK and feels neutral to me.
头 sometimes sounds like having a dialectal flavor to me. Also, the different combinations are not always the same. For instance,
里头 feels quite neutral but 东头 feels more dialectal to me.