Hi Folks, I'm just passing on an idea.
Rib racks seem to cost a packet for a cheap wire rack. As a very robust alternative, IKEA make a stainless steel expanding pot lid holder - http://www.ikea.com/gb/en/catalog/products/70154800/. It will hold up to six racks of ribs.
It only costs a fiver. The only snag is that they have plastic feet - however, these can be unscrewed.
I hope that this is useful.
Mat