Re: Jumbo Harrier
It's worth noting the F-35B can carry in the order of 15,000lbs of stores in total (when using the external pylons). The Harrier II can manage about 8,000lbs. It's basically got twice the thrust of the Harrier so can hover at twice the weight. It can also go about 1.8x as far and over 1.5x as fast.
So effectively if you want to build a really big Harrier. They have*.
*You couldn't just double everything up because scaling doesn't work like that, surface area increases with the square whereas volume (so weight) increases with the cube.