Thanks for the encouragement! It's not as if I'm abandoning O scale, just enjoying that aspect of the hobby a little differently.
There need be no worries at all. The N scale roster already includes 4 GG1s. 4902 in the Golden Spike Centennial Blue for the PC clockers, two Amtrak 900 series versions in black and red/white and blue, and finally 5 stripe DGLE 4935 which would also be correct pulling Amtrak.
I was able to dig out most of my custom painted Phase III heritage fleet cars last night as well. They were better than I remember them and included a dorm/baggage and a heritage lounge among some other misc. cars. Those are cars I still haven't found in O scale yet.
Photos to come!