An excellent topic as I feel that owning a Doll is as much a sensual experience as well as (for some) a sexual one.
I have a Fire Doll with a beautiful face but for me the mouth is too small to give a realistic sense of proportion in the kissing department.
As the OP states that he doesn't have a Doll (yet?) I hope that the advice and opinions given in this thread helps in selecting the correct Doll for his needs.
And if it's slightly wrong... ah well, buy another.