The P22 that Jamie is selling is at his yard, ie well inland! I had a look at it when I was there a couple of weeks ago and as far as I remember it had a PP jet, was just looking out of interest though! It is or was on boats and outboards - search for pacific.
The hydraulic pump on that one is driven by a toothed belt from the drive shaft, and I think there are control system problems there too. The one he had was fitted out as a jet boat by DMG of Southampton, not sure if they're still trading or not.
If you go the V8 route let us know how you get on as I am very interested... Sorry Pete I stil like the idea!
"I'm not lost, I'm exploring...."