Scott, since you have a vert, I would recommend the non-R.A.R.E. long branch manifolds from the usual places (Ames, CI, Year One, etc.) then get 2 1/4" header pipes from Year One (part #'s H01LH and H01RH, $76/ea.)that bolt right up, fit above the X-brace, and go back to where you can slap a couple of mufflers on under the back seats. That's what I did and it worked out fine.

Don't you need 2 1/2" pipes to bolt up to the R.A.R.E manifolds? That might take some fancy custom bending if you want to use the X-brace.