Cool. I think, with a max of about 4 throttles involved total, I probably won't need much power.
I'll see how it goes as the layout scales.
In the meantime, I've also plugged the UR92 in, in the center of the layout, and powered it up. It works great so far, so we'll see how that lasts as things grow.
Thanks again, everyone, for the help. I feel like I'm on solid footing now for future growth. I'll be writing the plan up on my website when I get a few minutes to rub together.