What plan would you suggest for for time builder that would be small enough to store and easy enough to build which would be suitable for kids to ride and alos adult main usage would be concrete grass would be nice.
It depends what you mean by "small enough to store". GRP hovercraft can quite easily be stored outdoors just like a boat.
One of the reasons why bigger is always better is that larger footprint craft have a lower cushion pressure AND lower cushion air losses. This means you can use a smaller engine (less fuel!) AND have a more capable craft.
Grass (unless bowling green smooth), like pebbles, can actually be a pretty difficult surface for hovercraft because of the high drag and cushion air loss. I would be surprised if the UH6F works well on grass at all.
You will quickly get bored sliding around a car park or concrete apron and all of the time and money put into building the craft will end up wasted - which is why we are trying to persuade you to make something a bit bigger that will be a true multi-use hovercraft
.
My personal choice ('cos I built one
for a first timer would be a Sevtec Scout - it's a very capable small craft that is easy to build (flat panel construction) and has excellent rough water performance (
check here). The 10x5.5ft version will carry two medium build adults or one heavy adult in all sorts of conditions. You should maybe also consider it's slightly bigger brother, the Vanguard (14x7ft)- it could be built for around £50 more than a Scout and will carry three adults.