well if I really had to choose a waifu that already exists I guess in nutaku version I'd have to say Clissa.
http://vignette3.wikia.nocookie.net/...20160309004245
I mean, even her AW art clearly shows her as waifu material.

otoh...still need Towa-chan in DMM. and probably Estelle as well. saw her H-scene and her cuteness boosted her ranking up a lot.