are their any hydrogen cars and hydro converters for sale in us?

150 miles a day. With the volumetric energy density of compressed hydrogen gas being 405 WH/l, that would mean a tank ten times larger than a typical gas tank.

Hydrogen converters don’t sell because they don’t work. It’s all sleight of hand to rip you off. The basic physics are that it takes more energy to obtain the hydrogen from the water then you get from burning it (285.83 kJ gets you 237.13 kJ in an ideal case though the 48.7 kJ difference can be recovered from the environment in steady state operation which means the absolute best you can get is 237.13 kJ from 237.13 kJ, in other words zero energy gained).

When Sandia labs researched more efficient ways to produce hydrogen from water, they determined that it was better to continue the process and synthesize fuels like methane, methanol, gasoline or diesel. Hydrogen is a terrible vehicle fuel because there are simply better alternatives and every time a actual scientific effort has been placed into researching it, it becomes apparent that technically you would be better off synthesizing gasoline however since marketing hydrogen cars means more cars to build, it may be possible for auto manufacturers to make more money at the expense of the environment by promoting hydrogen cars.

If all you want to do is refuel at home, convert your car to CNG (a very simple conversion), get a compressor and refill from the house’s natural gas line. It’ll be cheaper too, at least till natural gas prices goes up which it will.