Here is the Hot Head website with warranty information:
http://www.hotheadsource.com/HHtorch.html
Not all pages of the website are working properly right now if you click the link for technical information. It has been like that for a while.
Do you have an Asian source for the Japanese burners?
http://www.jplampwork.com/a3index.htm
More information on burners here, including what types of glass are recommended.
http://www.jplampwork.com/a3torch.htm
They didn't answer last time I wrote to them, but I haven't followed up on that.
Just for another option, here is a European crossfire burner using fuel and air.
http://lampwork.de/
http://lampwork.de/Bohmisches-Kreuzf...ngl_070628.pdf
You might look in your area for neon sign making equipment, as those burners are usually fuel and air.