One owner of a Super Nova based on the International chassis stated that the ride was very harsh, and they would be trading it in very soon. They only had 11,000 miles on it, and said it road like a truck.
At the time, I was also interested in buying a International Super Nova, and read it with interest. I thought I would need to replace the rear springs with air bags, and in a F-550 conversion this cost was about $2,500 - $3,500. I saw those conversions at Quartszite in 2002.
Another thought I had was to get a Ford F-650 with factory air ride, and have one built on that chassis. However there are many stock diesel pushers that will ride better as they came from the factory with 4-8 air bags. Some are rated to tow 10,000 pounds, like Alpine. They also come with much larger inline 6 engines, well proven in over the road truck usage.
I think I would be looking at Country Coach, and other diesel pushers in the same price range. One of the most unique DP's that I saw was a Airstream with a roof top deck. When I went into the dealership, and up to the roof (staircase is built in) the sales rep said they had a LOT of people looking at that one, but not buying it.
Fred.