It's hard to find one without the cargo add ons. I've asked why but it seems to be one of those mysteries of Chevy dealerships that no one can explain.
I got mine with the 1SA package and no add ons except the aux guage set, but I had to have it shipped in from 1200 miles away. Still saved me probably 7 grand.
I got a plasic container from Office Depot, and used tie-downs to tie it to one of the two cargo hooks. I use it to hold all the odds and ends, and I can just flip it up on it's side if I need to haul stuff. I also picked up a folding two wheel cart "As seen on TV!", for groceries and stuff.
I'm very happy with that setup.