The story idea isn't bad... but the way you've handled it so far sadly is. Since you said you're suffering writers block anyway, go back and rewrite the first two chapters. You don't need to add any new events; those you have so far are worth at least ten times as many words as you gave them. It would improve the story quite a bit.
As for pairing - I like Harry/many, so I'll say at least Hermione and Padma, and perhaps Tonks. Given the name of the story seven wifes would fit.