I have pre-built consists for many of these on the DLS - search for "GN Empire Builder".
As far as Amtrak's empire builder goes, the standard consist is as follows (using superliners, obviously):
2-3 P42DC or ALC-42 locomotives
Baggage
Transition Sleeper
2x Sleeper
Diner
2x Coach
Lounge
2x Coach
Sleeper
This is the usual consist for the segment of the route between St. Paul and Spokane, which would cover Marias Pass.