I have only heard of one person in the US with one of these, and I forget who they were, I almost suspect that retrofitting an older 1.3L Honda engine might be a better idea if you want to be able to use available parts, as you would otherwise be using an engine that not even Honda dealers had a parts list for.
With that said, I have dreamed of simaler ideas, I would start out buy getting ahold of either someone who imports mini trucks, or someone who imports Honda engines, as they are both going to be importing shipping containers of stuff from japan.
__________________
|