As much as I wish this were true it just isn't the case. Let's not embellish. That doesn't do anyone any good.
OP: Can a model RR be built in S? Of course! It depends on what you want though. Based off of your criteria of the 30's Santa Fe and being a locomotive guy, I'm gonna stop you right there... S is the perfect size, but you are not going to find much Santa Fe specific equipment, let alone steam in S. I am not aware of any S scale brass steam ever being done. Brasstrains does not list a single SF specific model. If you are ok with Hi-rail then you could get the Lionel AF Y-3 2-8-8-2 in SF paint as well as the American models 4-8-4 Northern (also available in scale wheels). Other than that I can't think of any more.
Not trying to be a downer, but this is where many of us live... Love the size and wish it were more popular, but it isn't. And it isn't growing. MTH buying S-Helper Service and now going out of business is a big hit. Lionel will likely keep dribbling out new products here and there, but realize that the scale Berkshires that just came out were being discussed 6-8 years ago. That's how long product cycles take in S.
I think you should decide if you want S for it's size and change your prototype, or model SF steam in a different scale.
Just my 2 cents...
While not Santa Fe specific, River Raisin did offer a model of the ex-B&M Berkshires that Santa Fe bought to ease a power shortage. (Too bad RR didn't offer the one that was "Santa Fe-ized"...) Plus the old SHS 2-8-0 is a "close enough" stand in for the ex-NYC 2-8-0's Santa Fe acquired with the Kansas City, New Mexico & Orient purchase.