newb looking to set up 2010 Chevy Express 3500

Thank you for that advice, I have been looking at truck axles for a swap rather than setting up a new gear set. Would this recommendation change with only pulling a couple times a year and day-trips the rest? I was also curious whether helper airbags would be of any benefit. I have not driven the van loaded to know whether seat of the pants says yea or nay, and I doubt the rear springs are too worn.