One of the main issues with replacing the plastic toilets with ceramic bowl toilets is the distance between the center of the hole and the back of the toilet. On the one you mentioned the distance is 11" vs 7 5/8" for the plastic model. On my 25fb I don't have the space for 11". So if you have about 3 1/2" to spare between your current toilet then you should be able to upgrade.
2008 Classic 25fb "Silver Mistress"
2015 Ram 2500 6.7L Cummins. Crew Cab, 4x4, Silver