Also, my horse trailer is around 40' long from the front of the nose to the back of the trailer. Also Yes you will notice a big difference between a bumper pull and a gooseneck as far as handling of your truck. I pull with a 2005 F350 Crewcab Dually Diesel jusst for the fact that it is more stable for hauling horses. There are ALOT of people that haul horses with single rear rears to and they pull a gooseneck with no issues either.
Where do you live?? I can help find a place close to you if you want.