Well, I would go with whatever is cheaper between the two. LOL.
Personally, I would go with RE XXX's or MT's. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Oh, and what size of boxes would either of these setups be in? The air space is going to be a big factor, especially having 4 subs sealed, the 2 W7's might be better ported because of larger air space.