I agree that you need to practice turns and backing in a large parking lot before you hit the road.  The road is never a good place to learn.  I had my wife driving out 19,000#, 40' 5er in a church parking lot on several Saturdays until she felt comfortable to get on a street with it.  She passed her Texas class A exempt license with no problems.
I also do not see the purpose of changing to a GooseBox.  If you are after a clean bed get the B&W companion slider.  Truckers do not use a ball hitch for their rigs.  They use a 5th wheel hitch.
Ken