Hi there,
be careful using this image as any basis for North American railroading in the late 1860s or 1870s. The set for this movie featured European ideas of what it looked like here, and the picture you have posted includes European cars standing in for US style boxcars.
There are some wonderful kits available for US prototype cars including passenger cars and other equipment. I would recommend you pick up a couple of back issues of 'Narrow Gauge and Shortline Gazette' before you start anything. These great magazines have featured some of the best work in this hobby and in the last few years this has included some high quality work in 1/32, 1/24, and larger scales. Almost all of these scales use #1 gauge track or 4' 8 1/2" from inside rail to inside rail in 1/32nd or various narrow gauges for other scales.
For parts consider visiting 'Caboose Hobbies' in Denver, Colorado... they have a pretty good online store and a great brick and mortar location if you are ever out there.
Good luck!
Ken