Curtis, Absolutely would love to see Atlas produce the SD70 series in O Scale, including the Spartan cab version, as I model the CN/IC as well! They certainly would make an incredible locomotive, but having not seen the Dash-8 yet, I highly doubt we'll see an SD70 anytime soon, let alone a Spartan cab variation. Just not holding my breath.
In terms of the gondola, I can't honestly believe they haven't produced this model already in O scale.