The short answer is no, we do not. At this time we do not have any kits or systems designed to generate Hydrogen on-board for vehicles. However, a quick Google search for HHOs brings up numerous kits and system suppliers.
However if you are looking in to building an HHO generator yourself, we do recommend taking a look at our Electrolyzer Membrane Electrode Assemblies (EZ MEAs). Our EZ MEAs are very efficient (far more efficient than a standard SS metal electrode) but certainly more expensive than a simple metal plate. They are made using a Proton Exchange Membrane (typically NafionTM) and a particular catalyst configuration designed to lower the voltage at which the electrolysis (hydrogen generation) occurs. For a little more about how electrolyzers work and how much Hydrogen you can expect, take a look at our previous article and our EZ Design Helper tool.
Working with an MEA based system is also probably a little more complex than most of the conventional HHO kits using simple metal electrodes. PEM based Electrolyzers are similar to fuel cells in that they are typically in a stack configuration, but there are different material concerns than in fuel cells (see the discussion on Gas Diffusion Layers for PEM EZ here). In addition, PEM electrolyzers use pure, ion free water (e.g. De-Ionized water) while many of the HHO systems will use a KOH additive or other salt/electrolyte.
So, if you are looking for a turn-key HHO kit, we currently don’t offer one. But if you would like to try to build your own, take a look at our webstore for our standard EZ MEAs. Let us know if you have any questions or need assistance with your PEM EZ design by emailing us at AskUs@FuelCellsEtc.com