The 83mm mod isn't a certain though, you need to do some pretty accurate measurements to check if there is enough room between the crank arm and chainstay. I've seen 970XTR's modified to fit on a Sunday and they sit within a gnat's whisker of the chainstay.
Having run the Atlas's, they are fine. The BB is junk though and the splined interface is a complete ballache compared to the simplicity of Saints. Fine if you get lucky and manage to set up your chainline & chain device perfectly first time (never happens), but after you have removed/reinstalled them 5 or 6 times you will curse every single pound you spent on them.
Middleburn have finally joined the modern age & there are some pictures of a prototype external BB crank floating around now. If you really want something different, buy the Saints, run them until the Middleburns show up then swap them out.
PS – you're not Bream off the MLR by any chance are you? If so, its a small world.