You don't really need a rom, unlike iOS, you can change everything on your phone with just rooting. And there should be a lot of iOS launchers out there. You can also install miui and browse for iOS themes. I don't expect anyone to waste time on making an iOS 7 rom because we are already having a hard time adjusting to kitkat right now, im guessing a lot of devs have their hands full. If you want to make one with jelly bean, you are welcome to read the guides all around the forum.