Hey Mike,
fair enough, remember it is all about the RIDE and what works for you. I have risers fitted to my 3 retro hardtails myself as well. You could likely get a RaceFace bar to complement your other RF parts and matching the Easton for rise and sweep.
My comments were based on a conceptual idea of this build and Easton just doesn't fit the bill for me. One of those 70cm wide flatbars would look just right on your build. I have a 71cm Madd trials flat bar in the shed waiting for the "right" build, it could well end up on my Sinister one day.
Enjoy!!