Your best bet for a tourist operation--if you want variety--is do something where there's also a freight operation. Like:
1) The Strasburg RR
2) The Sierra RR
3) The Black River & Western RR
4) The Everett RR
5) The Gettysburg RR
6) The San Luis & Rio Grande RR (tourist trains were operated under the name Rio Grande Scenic)
7) The Reading & Northern RR (tourist division known as the Reading, Blue Mountain & Northern)
And many, many others...
So yeah, there's precedent. And, if you're freelancing, you can always toss in a tourist operation...but use caution and look at what the real railroads do. The Strasburg is a rare beast with its 19th-century passenger equipment. Beat-up heavyweights or transition-era commuter coaches are more probable (or, like on the old Bel-Del, they have a Chinese 2-8-0 pulling former Long Island Rail Road commuter coaches that were in commuter service into the early 1990s).
Our own
@DKS had a tourist operation side-gig on his freelanced White River & Northern RR.