Lots of options
I can think of a couple of options. A Cyclone, if they are somewhat water tight. Or Ghost and Pablo's jackshaft. It has a rear disc brake so with of of Andy's sprockets you could also do a HT in the normal fashion or a Straton rackmount.
It was pretty late when Simonator (hope I got his name right) IMed me with a link to a pic of this. My 1st thought it was some mad scientists one off creation. Then I found it was in production! I pull out my wallet then I remembered I was married and all major purchases have to be approved by committee.
