I've done a few cabooses for folks with the MTH HO fan driven smoke unit. It doesn't get hot enough to melt the caboose, and it puts out a decent volume of smoke, just about right for a caboose. I pair it with a small AC-DC power module to provide power.
Indeed. So if you're not inclined to mess with electronics and such, you can also commission someone to be the manufacturer.
In the opinion category, the fan really helps to blow out the smoke to get a healthy stream. AFAIK the Lionel EV caboose shown in the video above does not have a fan. The video shows it moving, but the first one that came up on youtube showing it stopped.
This one was purchased "used" but discounting that, note how without a fan, smoke can settle in the caboose itself and leak out the bottom. Additionally, when stopped (which it may never be on your busy RR) smoke tends to settle around the stack which may be a who-cares but to each his own.
I found this video of a fan-driven (using an MTH HO smoke unit like GRJ mentions) of a stopped caboose. Again, to each his own.