The great marriage argument must go on.
Naruto
I'd like to note that Naruto's family situation and childhood are completely different from Sakura's, but, surprisingly, such differences make those two compatible as a married couple. Soon you'll see why.
What do we know about Naruto's family? They were a loving young pair who had to sacrifice everything (including lives) while leaving their helpless baby-boy an orphan endowed with a special gift/curse. Yet the nine-tails was not the sole thing they sealed into him. Naruto got his mother's unyielding vivacious nature and his father's noble aspirations. Somehow, Kushina and Minato had managed to pass on the most precious legacy to their son - spiritual strength.
So Naruto grew up an orphan yearning for affection: parental, friendly and romantic. He has his needs, alright. And one of them is having a family of hiw own, a real one. Especially after the incentive talks, provided by his mother and father. The story of his parents' love and Naruto's birth has filled the void where the family legend commonly resides. After catching a glimpse of a happy union, Naruto would definitely desire to start one, so he could carry on Minato and Kushina's dream, which, sadly, had been tragically interrupted. That is why I'm sure that he finds future marriage an appealing idea. Although, this motive may seem undeveloped and blurry, along those general lines: find the right girl and become the right man for her. Personally, I think that Naruto has taken a proper approach. His simplistic plan is steadily reaching fruition.
The right girl is Haruno Sakura. Undoubtedly. And I hardly see that constant changing. Naruto's godfather (Jiraiya) was a one-woman man, Naruto's father was a one-woman man, and, guess what, Naruto will also love one woman all his life. What criteria should his dream wife meet? Just one. She must be Sakura-chan.
Why her? Perhaps, Sakura is a challenge. Facing and overcoming challenges constitute Naruto's way of being a ninja and lover. Remember that, as a little boy, he had to fight for attention, both positive and negative, (and affections) of others (Iruka is a prime example). That's how he learnt to seek out and cherish the tiniest signs of emotions. In other words, he's a glutton for emotional reactions. Our explosive, brash and responsive Sakura turned to be like a magnet for the boy to play with. He became attached to her easily and... permanently. Ironically, her crush for Sasuke proved to be the reason behind it. Her crazy drive to be approved by the very object of her fantasies brought her closer to Naruto: they shared the same goal. Naruto liked how devotedly Sakura liked Sasuke and decided that he wanted to be loved like that. And for him it actually meant to be loved by Sakura (no one else could love like her). But as time passed, this relatively childish intention matured into loving Sakura almost selflessly. In my opinion, Naruto chose to guard Sakura's happiness, her way of loving, as strange as it sounds. It doesn't matter, if they marry or not, Naruto will keep on protecting Sakura's way of love, and she'll always remain a challenge for him at least from this particular point of view.
They balance each other nicely. Sakura's selfish, Naruto's can be selfish too at times, but he makes her needs his priority. That's how he may act selfish - by trying to be the hero for her. Another of Naruto's good qualities is being open-hearted. He's not a love miser, but a squanderer (and can be overbearing at times), leaking affections. And Sakura is his ideal absorbent because Naruto doesn't need to get a lot in return: her joyful sincere smile is already enough for him. Naruto may act like an oaf (and a diplomatic disaster), Sakura is the one to criticize and direct him. When he doesn't understand something (chakra theory, for example), she's the one to explain. And vice versa. If Sakura attempts at lying (even for her friend's benefit), Naruto is the one to reveal the truth and teach her that frankness is their best adviser. Relationships are built on mutual trust and encouragement. Naruto would be the husband who wouldn't acquire an inferioty complex about Sakura's accomplishments. He'd strive to make them even more evident and wonderful. And Sakura would support him through and trough. Even if they had arguments, Naruto (like Minato) can be dovish and doesn't bear grudges in the first place.
Naruto and Sakura already share the hokage dream. Actually, they share at least one more dream (without realizing the fact). Both hope for a family where nobody would feel lonely. And it takes two people to build it. Naruto, being an orphan, even if he happened to know his parents' story, doesn't have a solid reliable family model, but Sakura does. There are so many other things they could give each other. Too many to name. At last (but not least) Naruto's resourcefulness and Sakura's special medical knowledge can enrich the couple's lovemaking routines, bringing in the adventurous spirit. 
I only disagree with one thing in here, and that was when you said that Sakura was selfish. Everything else is really good though!