The company that makes these prebuilt hho conversion kits is proud of them but they look like quality products.
I am not sure what their track record for refunds and customer service is.At least you can get some good ideas for making a stainless steel body hho conversion kit.
I especially like the idea of using stainless pipe with rubber end caps held on by radiator clamps. If for some reason, there was ignition, the end caps would just rupture instead of having glass shrapnel like you would with a glass jar hho container. Rubber caps are easy to find at any Home Depot, Lowes, or Ace hardware and radiator clamps are easy to find too.
The rubber is a good insulator so electrodes can be fastened easily too.
There is another video of a 2000 Ford Ranger truck that uses a design similar to this and he uses kitchen stainless steel spatulas for the electrodes. He claims 30 percent increase in gas mileage.
According to the guy in the video, placement of the hho tube before the mass air sensor works best. He also is insistent that a little bit of hho goes a long way and that too much hho is bad. That kind of contradicts what most hho experimenters think since everybody wants to get the best hho production possible .
Here is the video of the 2000 ford ranger hho conversion.