There are some people that run boats like that on the New R. in WV. The NPS rangers run 14ft cats with a jet outboard. Not sure of the size of the jet, but it's not small. Looks like a blast and would like to build one myself someday.
I know one guy who has done the same with a bucket boat and constructed a slatted floor (like the slatted floor on an intex mariner 4) to stand on...he was using a caged prop motor that would kick up when it hit a rock. He seemed to think the caged prop is better than a jet, at least here on the New.
These are all run on real deal class IIIs
He sold it not long ago and is building another...I would think the one he is building would be a cat.