You may try
RV Business Magazine. It is a trade publication that you can read online Free of Charge.
While not Class A specific, it will tell you who is going in and out of business, who is moving where, which suppliers are coming out with new products and which manufactures they are selling them to, etc
Pretty Neat stuff, and you sure can't beat the price.
2015 Jayco Greyhawk 31DS
2013 Ram 1500 Laramie Hemi
2008 Yamaha FJR Sport Touring Bike in the bed of the truck