Heightmap is (64 * map size) + 1 for each dimension, so 513x513 for an 8 x 8 map. Building a map from scratch that way is not recommended, however, as mapconv is a piece of garbage and SME doesn't import metal maps correctly.
I can't even remember what the size for diffuse tex is, but the resolution is much higher. All of that stuff can either be looked up on spring wiki or just create a new map in SME and then export the maps to get the proper texture size anyway. Given those facts, plus all the mapmaking info already in the ZK forums which he obviously didn't bother searching, my impression is that any advice is a waste of time because nothing is likely to materialize from it.