Alanrail, If you go with phase IV the locomotives would be Genesis locomotives in the current "blue wave" scheme or any of the Amtrak 2011 anniversary Genesis locomotives. The selection just released this week by MTH would all be candidates. There is a phase IV painted Heritage unit that has the same stripes, as MTH likes to call it, "5 stripe." Trains with this consist would include, Lakeshore Limited, Silver Meteor, Silver Star, Cardinal, Crescent, and the discontinued Three Rivers.
As far as GG1, they would never have pulled any phase IV painted cars as they were retired before that. I'm not even sure they would have seen the phase III Viewliner equipment but maybe, I would have to verify GG1 retirement date vs Viewliner rollout dates. The phase III Amfleet would likely have had GG1 power, but if GG1 is your power goal, go Amfleet phase 1 & 2, that's the common matchup. Viewliners were not even an idea yet during phase 1 era Amfleet.
The AEM7 would have pulled phase III, phase IV. There could have been a few Amleet phase 1 cars in the mix when the AEM7 first rolled out.