I know nothing has been posted in this topic for months, but the Hoverwing was featured on yesterdays gadget show. It gives a bit more information on it including size of engine, how fast & how high it can go
Basic spec $25k,
Military spec $90k
If you want to catch it on the big screen it is repeated Saturday morning. If you can manage with computer screen the link is here
http://fwd.channel5.com/gadget-show/videos/feature/hoverwing-2