Go for a suite if you need to share a room. As Tom-n-Cheyl said the rooms are small. The other problem will be closet space. With 4 in room the suite can't be that much more and the perks are a lot better. The other option could be is getting a inside close by.
If at all possible I would recommend not doing a quad with 4 adults - 3 can often be tight, but I am afraid that at those close quarters - the four of you may no longer be friends after the cruise is over.