If my leaf blower emits 20 horse power then my hovercraft will lift 200 ponds
"emit horse power" is VERY hard to measure. Taking a bit of a detour into engines "developing horse power" in the automotive industry is measured by a simple engine dynamometer; however, to measure horse power delivered to the drive wheels, the measurement is extremely difficult and expensive and requires specifying a lot more conditions. A hover craft is an even more complex measurement problem because it invoves fluid dynamics and not the simpler mechanics in the car example. End of detour.
A hover craft is all about developing a pressure differential sufficient to lift its weight while delivering enough volume of air (cfm) to maintain the pressure. The perimeter length of the skirt, the skirt design and its ability to conform to the surface it is hovering over will determine the leakage per unit of perimeter per minute which will determine the CFM required. The area under the skirt and the weight of the craft will determine the PSI required to lift. The efficiency of the fan at the PSI and CFM and resulting rotational speed will determine how much energy is required (e.g. horse power needed).
BTW: Have you looked up the horsepower ratings of leaf blowers? You are off by at least a decimal point in reality in their "input" horsepower and their "output" horsepower is a small fraction of their input.
From an engineering perspective, I doubt you can safely experiment with any hover craft like apparatus that is self contained. The weight of the motor and fan will be a significant portion of any hover craft and until you use exotic multi-stage turbine compressor designs like jet aircraft engines, they won't be able to lift their own weight using air pressure under a skirt. I'm not recommending giving up, I'm recommending scaling back to experimenting with an external air source and some small hose connected hover craft models and finding an easier hypothesis to test.