To be honest, not too sure yet! I am having the Raincoat made though so that will be what brings it together.
I thought that maybe the problem that you were having was because the clothes that your bashing are adding a little too much bulk thus making the head look smaller.
The head is sized the same (or a touch bigger) as the average HT sculpt so I don't feel that it's pinheaded; or at least my stock build up doesn't appear so in hand.
The figure straight from Iminime was built on the ZCWO body if that is of any help to you; I think that how the head looks in proportion to the entire figure will be based on the clothes you choose more than the body