WEBSITE - http://www.x-sail.com/product/prices
There are a number of manufacturers for Land Yachts and I have sailed most of them but my opinion is that the X-Sail is good value for money and could be sailed by most disabilities.
Don't buy one on spec.... find a club or 'fun day' that will let you try one.
They are easy to transport and set up but need quite a big area to be much fun.
They do not need a great deal of wind to sail on tarmac but may need a push on grass or sand.
Remember they do not have brakes so needs some common sense in use.
It is fun to sail them tipped on two wheels but if/when you capsize you must not try and save your self using your arms.... they will break... keep hands inside even when you are an your side.