I've got a Tubus Cargo rack and it is extremely well made and light considering its strength. Velo-Orange.com sells a knock-off version for less money that is stainless steel, but they are currently out of stock.

http://store.velo-orange.com/index.p...urs/racks.html

That said, I removed my rack after using it for one month because I didn't need it for commuting. I use a Carradice Barley for commuting and it is large enough to carry everything I need. Panniers with a rack would be much heavier and provide a lot of un-needed space for my needs.