Small turbojets aren't a problem - you can buy them commercially and hold them in your hand, producing about 15 lbs of thrust (a whole lot more for slightly bigger versions) Check aeromodelling press. I hope the guinea pig has ceramic on the heels of his shoes, because these babyjets run as hot as their full sized counterparts.
I don't notice the fuel tanks either, because they are seriously thirsty (anything that does 120000 rpm consumes fuel at litres per minute, even at these sizes)
Oh, and I hope he has a head for heights, because he'll be jumping from somewhere a long way from the ground. Even with lifting body aerodynamics, all that outfit will give you is a controlled fall maybe a little in advance of a base jumper's flying fox suit. You can miniaturise just about everything except American military personnel and unless you can ignore every law of aerodynamics (a la F104 Widowmaker) this gizmo will be all about power to weight ratio.