I'd save money, by NOT moving the toilet. Turn the current shower space or most of it, into a nice linen closet, Use a 72 inch vanity, leave the toilet alone.. You may not need the storage now, but you WILL when it's a kids bath. Having that linen, will allow a much more "open" looking vanity and custom at 72 inches is no more than ready to go. Two kids can share it with no issue, provided there is other storage. Don''t waste money on fixture moves. And unless you feel you truly need it, consider just the shower/no tub. A two bath house is an issue today anyway. : )

Even WITH a move of the toilet, I'd use the toilet space for tall storage at the depth of the vanity ( 24 inches wide) ..........or rue the day when you have two kids using it. What makes a space look spacious? A lack of visible CLUTTER.