Oh, I didn't even see the flaked wheat....yeah, that'll do the trick too. I used rye simply to back up the chocolate rye. In all honesty there is very little "rye" flavor in such a bold beer, but I bet it will be a tiny bit different without it, know what I mean?
I'm drinking one of these right now actually, and it really is a good stout!
FYI, my experience with pale chocolate is this: Pale chocolate malt = toasty bite while chocolate malt = slightly roasty bitterness