Lets say your plane weighs 30 lbs... In order to hover you must produce 3 lbs of thrust
at any time for the rool and pitch axis...

Lets say you steel %20 of the mass flow of the bypass flow for the puffer jets...

13N ~ 3 lbs

13N = 0.18kg/sec * 72m/s

72 m/s is around 161 mph... Doesn't sound too fast.. If you use a large ducts
you may get your 3 lbs force...

What I don't know is the pressure behind your bypass fan... A good guess
is around 2 psi.... You may want to test your bed stand with large volumes
of air at 2 psi and see what you get...

One thing is for sure... your valves on the wing tips and tail will need to
be large and fast...

I made a small bedstand with 40 psi and did not get jack for thrust...

Hope this helps..

Eddie Weeks