I'd have to see the locomotives, though I suspect it'll be a tight squeeze with the full Cruise Commander and RailSounds Commander in either of those. I put the full CC and RS into a semi-scale once, and every square inch of space was used, they were really stuffed in there!
There isn't that much risk of frying the CC-Lite with proper protection. I got brave and stalled the motor in the K-Line Interurban setup to see if the PTC would do it's job, no problem. It survived several tests, so I'm thinking that's a reasonable solution to the possibility of stalling the motor. So far I haven't seen any effect during normal running, even on grades with a few cars, the Hogwarts locomotive doesn't miss a beat.
The bonus with the CC-Lite is that it's really cheap until the end of the year, so you're risking very little money as well. 
If you get the electronics all into the tender, adding the fan driven smoke and Super-Chuffer in the boiler is no problem, lots of space. Might even be room for a second speaker to distribute the sound, that gives a nice effect.
