Partner- out of Idaho that makes the spendy-nice stoves actually makes one out of steel. The unit consists of 2 square-like trays-one fits within the other. They slide apart for use. Unit has 3" sides to pass any ranger inspection you'll encounter, fits inside a rocket box w/room to spare for briquets and a grill, and is pretty light.
I've used the magnum-sized nrs style fire pans, ones made out of the bottom of a 50gal drum, other round home-made kinds... I really like the slide out/together Partner one for its simplicity, fairly light weight, adjustability of size, and they're pretty affordable too.
See'em at the Partner web site and I think River Connection in Idaho sells them online.