Hi sd455dan
If you have the puck system installed in the bed of your truck for the fifth wheel hitch you may already have a centre hole that you can just drop a ball into for the goose neck trailer.
Redlands Okie has given you some great advice regarding turning. I ordered my third dump trailer as a tri-axle bumper pull because I usually have a cap on my truck and didn't want a gooseneck. I couldn't get a dual axle trailer that couldn't handle the trailer's weight and my latest Kubota tractor with accessories so I had to go to the tri-axle. You definitely want to minimize tight turns - especially on asphalt and loaded. I always do any tight maneuvering with the trailer empty and ready to pull straight out once loaded if possible.
My 2015 F350 dually with the max tow option is rated for 19,000 on the bumper hitch so that is adequate capacity for me. I have had some heavy loads of stones in this trailer and she pulls real nice so I think you will like the new trailer.
Regards,
Lauren