The Go One could easily be electrified and may be one the velo furthest along in terms of commercial production since it's been around for a while. http://www.go-one.us/
Other than the low seating, my concern about those short wheelbase tadpole velos is how they handle speed and real road conditions, imperfect surfaces. I don't doubt that they are fine at 40-45kph, high human power speeds, but are they safe at 40-50mph which would be easily achievable as an electric? Personally, with electric drive, a similar design but significantly bigger without too much more frontal area and allows room for a rear passenger plus storage would make them a much more useful vehicles. I realize it may require some motor vehicle status in most areas.
I think the Aptera may have tried to take too big a step shooting for a total car replacement. I truly believe there's a place for something in between the Aptera and the vehicle in the original post as a city vehicle. Sure the extra weight will reduce efficiency, but a reduction from 1000mpg to only 500mpg is nothing, because the operating costs at 500mpg is virtually nothing. You're also looking at a sub $10k vehicle instead of $30k+. I just think all the manufacturers are missing the mark with current EVs, with golf carts coming the closest.
Currently at $8K to $10K - too much $$$. Hopefully they will really ramp up production and drop cost.
If you were willing to put in the time, it seems like it wouldn't be too hard to build a fiberglass shell around an off-the-shelf trike. that would probably get the cost to ~3K.