Jim,
Redsquel here has a very nice one in the yellow snow master, the former Pedersen machine. Don't know if it is spring or air ride, but I would guess air. Very nice. Hope he see's this and chimes in. Don't know what mods were done to make it work though. The bench seat behind it looked pretty short. When I sat down it just said "cuoooosh..." and I was in love. Been thinking about it ever since. His machine does however have a 4" extension below the hard top, so he has more head room too.
Regards, Kirk