Have your town in a valley, ie near mountains, then the miners can come down from the mountains. If you have a railroad then cattle men and farmers will want to come into the town to sell there produce to the railroad or to ship it back east and that will in turn give your town a reason and a way to have the wealth to attact the bank robbers and cattle rustlers. If you make it a county seat then you can have both a county sheriff and a town marshall. Maybe put in a federal court so you can have a Federal Marshall as well. The Railroad can also bring in those pesky Pinkerton boys, as well as some foreign elements. All of these factions can lead to some real fun gaming possibilities.
The railroad tracks can also divide the town so you can have two styles of buildings, one on each side of the tracks. If you put in a water course, then you can have the town divided into quarters and have 3or 4 styles of buildings, ie brick , adobe, wood, canvas.
Don't forget outhouses, sheds, awnings, hitching posts etc. They make the town really look "lived in."
I have used a lot of Arnica Real Estate buildings in my town, as well as some scratch built stuff. You might also check out the ERTL brand of toys, they made a western town set that gives you several useful buildings, that while very shiny plastic, will weather up nicely.
You can also watch lots of western movies now as "research"
Good luck and glad to hear your wife is involved.