Or A Very Large Quadcopter, because they already know a thing or two about making large rotating airfoils with a hub full of neodynium and coils?
My guess would be range is the limiting factor, helicopters struggle keeping themselves in the air for more than a few hours, before taking into account any meaningful payload. Fixed wing aircraft can achieve so much more range.
Well, there are no large blimps/airships in production. Also, they are quite sensitive to windy conditions, and you want to errect the turbines in very windy places...
On the other side, building a small amount of rather simple airplanes should be quite doable in todays day and age.