Does anyone know of a set of airbags that will work on a 99 2500 4wd that mount over the axle not the leaf springs (so I can keep my over loads) and they need to work with a goose neck or fifth wheel mount.

There are certain bags that are made to mount over your factory overloads. I don't remember which, but if you call the manufacturer of the bags, I'm sure they can give you the right part number.

As for the GN hitch, the only solution I have found includes cutting the bag mount and modifying it to work.

AFAIK there are no bags that mount to the axle like the 3rd gen bags do.

I just bought a truck that had air bags with the goose neck hitch. They had the air bags that mount over the overload springs and the top air bag mount was welded to the goose neck reinforcement frame. If I remember right the upper air bag mount used the same bracket as if mounted to the side of the frame only it was welded to the G/N frame.

I was in the same boat so 8 got the ones that mount over leafs rings and modified them to fit on bottom out blocks. Not the greatest but been working for 4 years now.