That makes sense that it gets divided by amperage. I suppose I'll have to find myself a motor or four and get the amperage rating off them.
The D408SR (which I will look up) does sound appealing. That size isn't too bad. This is technically an O scale application but I want to run motors for other stuff; not locomotives.
And on that note, does the horn count as an aux output? How does the sound file for the horn work on a decoder? Can you upload your own or do you have to buy one with the horn you want?