i used an ISX 6 on the prophet as it has a regressive suspension design, the IFP chamber volume and pressure can be adjusted to ramp up at the end stroke, it worked very well as I could run reasonable air pressure to get the right sag and a good small bump feel and never have it bottom out hard.
I am using a DHX5 now and that is really nice… but heavier!
the Jtech tuned ISX is up for sale if you are interested it is a 200×50.