@sirius180 I think Kawasaki would be off the list, she's mentioned in an OVA that she was concerned about the inheritance level due to her number of siblings. For some reason I can't see Yui (I think she's the best girl because of her loyalty, shown public level of affection for him, and has had his back in a few episodes) or Iroha (she seems like she'd manipulate her man to work for her benefit, not the other way around) providing the cash flow enough for 8man having the house husband level of lifestyle he deserves (lol). Haruno and Yui seems like both of them wants to maintain the family reputation and are too controlled by their mother, so they can't marry a house husband and maintain the approval.
Then who are the possible candidates, or who's left? Hiratsuka can be the possibility because well... she's single, desperate, and...scary. Ebina if 8man is willing to gay whore himself out. Of course that is if 8man is truly serious of being a house husband.
In the end I believe Yuki will be the one by the process of elimination. She was the first girl about 8man's age he interacted with on an initial emotionally void, hostile (goes head-to-head against most), small breasted, non-childhood friend, which most manga/anime seem to like to end ships with. Yui is eliminated because they made her to be the big breasted, airhead, and somewhat clingy nature making the relationship too easy to develop therefore too boring for the author to develop. Iroha (I think if the author could do it over again, he would use her more because she's one of the more interesting characters), Kawasaki, and Ebina are eliminated by their lack of "screen time" in the stories. Haruno and Hirasuka are eliminated simply due to being obviously older from a manga/anime perspective, it seems they never pair up a couple with that high of an age gap of a younger male/older female. Totsuka is eliminated due to being a comic element of distraction.