is this a production truck?

i have seen 3 of them was wondering if anyone knew anyhitng about them>?

It's a Centurion conversion. Not GM production. A guy on FSC has 3 of them. In fact, that looks like one of his.

I would love the cab with a long bed would be one heck of a truck. is there seating in the EXT part of the cab or just storage?

It looks like the back seat is a convertible bed type out of a van.