I don’t know your process or how much ethanol we’re talking, but It seems like it would be cheaper (probably much faster as well) to build a vacuum still for recovering the bulk of the ethanol, then finish it up in a smaller roto like your 5-liter. @Roguelab is working on one shown in this thread that looks like it would serve your needs.
You might also find this thread useful.
There’s also a few threads about falling film evaporators, but those might be beyond your budget. You could probably get away with building/buying a still that isn’t under vacuum as well (much cheaper), but you might run into problems exposing your extract to that amount of heat for an extended period like that. Unless you don’t mind that. Just make sure you choose a heating method that isn’t direct flame or even an internal heating element. That’s one safety issue that stood out to me with the “weed witch”. It looked like they’re heating the boiler with an element that’s inserted into that bung hole. If that’s the case, I’d constantly be worried about ignition when distilling such high-proof solvent.